## 21-cm_line 21-cm_line ALT "21 cm line" D "21 centimeter line of hydrogen" BT radio_recombination_line RT H_I H_I_absorption H_I_cloud H_I_content H_I_emission H_I_region hydrogen radio_frequency ## 53_Persei_star 53_Persei_star D "53 Persei star" BT B_star pulsating_variable_star ## Abell_cluster Abell_cluster D "Abell cluster" BT galaxy_cluster ## aberration aberration D "aberration of light" RT astrometry coordinate_system ## ablation ablation D "ablation" RT meteorite ## abnormal_spectrum abnormal_spectrum D "abnormal spectrum" BT spectrum RT peculiar_star ## absolute_magnitude absolute_magnitude D "absolute magnitude" BT magnitude RT Hertzsprung-Russell_diagram Wilson-Bappu_effect distance distance_modulus luminosity ## absolute_temperature_scale absolute_temperature_scale D "absolute temperature scale" BT temperature_scale NT Kelvin RT celsius_temperature_scale temperature N "ES: moved Kelvin from RT to NT (2007-OCT-8)" ## absorption absorption D "absorption" NT atmospheric_extinction intergalactic_absorption interstellar_absorption light_absorption RT Rosseland_opacity atmospheric_scattering atmospheric_window capture equivalent_width interstellar_gas opacity photodissociation photoionization radiation radiative_equilibrium reddened_star reddening transmission N "combine with other terms" ## absorption_coefficient absorption_coefficient ALT "absorptivity" D "absorption coefficient" RT Einstein_coefficient atmospheric_extinction intergalactic_absorption interstellar_absorption optical_depth transparency ## absorption_line absorption_line D "absorption line" BT spectral_line NT absorption_line_system RT Lyman_alpha_forest Voigt_profile atomic_process bound-free_transition calcium_line cyanogen_line line_formation line_identification line_profile line_ratio metal_line microturbulence residual_intensity spectrum spectroscopic_analysis ## absorption_line_system absorption_line_system D "absorption line system" BT absorption_line system RT quasar HN "ES: new (2007-OCT-8)" ## absorption_spectrum absorption_spectrum D "absorption spectrum" BT line_spectrum spectrum NT atomic_spectrum RT Balmer_series D_line Fraunhofer_line Raman_effect bound-free_transition energy_spectrum ## absorption_spectroscopy absorption_spectroscopy D "absorption spectroscopy" BT spectroscopy ## abundance abundance ALT "chemical abundance" "element abundance" "stellar abundance" D "abundance" NT cosmic_abundance isotopic_abundance metal_abundance overabundance underabundance RT CNO_anomaly abundance_ratio chemical_composition chemical_element chemical_evolution curve_of_growth element_formation enrichment heavy_element helium-poor_star helium-rich_star peculiar_star rare_earth N "may be combined with element, e.g. helium abundance" ## abundance_ratio abundance_ratio D "abundance ratio" RT CNO_anomaly abundance ## acceleration acceleration D "acceleration" BT kinematics RT deceleration gravimetry orbital_element orbit ## accretion accretion D "accretion" RT Alfven_surface accretion_disk binary_star mass-transfer particle_accretion ## accretion_disk accretion_disk D "accretion discs" UK "accretion disk" BT disk RT accretion black_hole circumstellar_disk close_binary_star cooling_flow dwarf_nova low-mass_X-ray_binary_star stellar_wind superhump ## achondrite achondrite D "achondrite" BT chondrite meteorite ## acoustics acoustics D "acoustics" RT acoustic_wave ## acoustic_wave acoustic_wave ALT "sound" "sound wave" D "acoustic wave" BT wave RT acoustics gravity_wave sound_speed wavelength ## actinium actinium ALT "Ac" D "actinium (atomic number 89)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## active_galactic_nucleus active_galactic_nucleus ALT "AGN" D "active galactic nucleus" BT X-ray_source galactic_nucleus variable_source NT Seyfert_nucleus blazar RT BL_Lacertae_object active_galaxy compact_nucleus emission_line_galaxy galaxy quasar radio_galaxy ## active_galaxy active_galaxy ALT "eruptive galaxy" D "active galaxy" BT X-ray_source galaxy RT X-ray_flare active_galactic_nucleus compact_galaxy emission_line_galaxy ## active_optics active_optics D "active optics" BT optics RT adaptive_optics atmospheric_refraction multiple_mirror_telescope seeing tip-tilt_mirror ## active_prominence active_prominence D "active prominence" BT active_region prominence RT Sun ## active_region active_region D "solar active region" NT active_prominence RT Sun HN "FVH: new (2007-OCT-29)" ## active_star active_star D "active star" BT star NT X-ray_star emission_line_star RT X-ray_flare ## active_Sun active_Sun D "active Sun" BT Sun RT flare quiet_Sun solar_activity solar_cycle sunspot ## activity_index activity_index D "activity index" RT solar_activity ## adaption adaption D "adaption" N "combine with other terms" ## adaptive_optics adaptive_optics D "adaptive optics" BT optics RT active_optics atmospheric_refraction seeing segmented_optics ## adiabatic_process adiabatic_process D "adiabatic process" RT energy-transfer thermodynamics ## adjustment adjustment D "adjustment" RT alignment_optics collimation correction optics orientation N "combine with other terms" ## adsorption adsorption D "adsorption" RT dust_grain interplanetary_grain interstellar_dust N "combine with other terms" ## A_dwarf A_dwarf D "A dwarf star" BT A_star dwarf RT A_subdwarf ## aerolite aerolite D "aerolite" BT meteorite ## aeronomy aeronomy D "aeronomy" BT scientific_field RT Earth_atmosphere atmosphere planet ## Ae_star Ae_star D "Ae star" BT A_star Herbig_AeBe_star early-type_emission_star NT Herbig_AeBe_star RT Be_star ## afterglow afterglow D "afterglow" BT atmospheric_radiation RT light_scattering luminescence ## age age D "age" RT Hubble_time cosmochronology relaxation_time turnoff_point N "combine with other terms" ## A_giant A_giant D "A giant star" BT A_star giant ## air air D "air" BT gas RT atmosphere ## air_conditioning air_conditioning D "air conditioning" RT temperature_control ventilation ## airglow airglow ALT "dayglow" "nightglow" D "airglow" BT atmospheric_radiation RT Rayleigh_scattering ashen_light aurora night_sky_brightness radiative_recombination sky_brightness ## airplane-borne_instrument airplane-borne_instrument ALT "airplane borne instrument" D "airplane-borne instrument" BT instrument RT balloon-borne_instrument ground-based_astronomy infrared_observatory rocket-borne_instrument satellite-borne_instrument ## air_pollution air_pollution D "air pollution" BT pollution RT light_pollution site_protection ## Airy_disk Airy_disk D "Airy discs" UK "Airy disk" RT diffraction ## albedo albedo ALT "spherical albedo" D "albedo" BT optical_property RT illumination radiation reflection surface_property ## Alfven_surface Alfven_surface D "Alfven surface" RT accretion neutron_star ## Alfven_wave Alfven_wave ALT "hydromagnetic wave" D "Alfven wave" BT magnetohydrodynamics NT coronal_wave ## Algol_variable_star Algol_variable_star ALT "beta Persei star" D "Algol variable star" BT binary_star eclipsing_binary_star RT W_Ursae_Majoris_star ## alignment_optics alignment_optics D "alignment of optical image" RT adjustment collimation correction orientation ## all-sky_camera all-sky_camera ALT "all sky camera" D "all-sky camera" BT camera wide-field_telescope NT cloud_monitor RT all-sky_photography wide-angle_lens CN "FVH: added NT CLOUD_MONITORS (2007-SEP-21)" ## all-sky_photography all-sky_photography ALT "all sky photography" D "all-sky photography" BT photography RT all-sky_camera camera wide-angle_lens ## almanac almanac D "almanac" NT nautical_almanac RT ephemeris ## alpha2_Canum_Venaticorum_star alpha2_Canum_Venaticorum_star D "alpha2 Canum Venaticorum star" BT eruptive_binary_star magnetic_variable_star RT Ap_star SX_Arietis_star spectrum_variable_star CN "FVH: removed incorrect BT cataclysmic_variable_star (2007-OCT-2)" ## alpha_particle alpha_particle D "alpha particle" BT boson composite_particle nuclear_radiation particle RT electron neutron proton radioactivity ## altazimuth_mounting altazimuth_mounting ALT "alt-azimuth mounting" "azimuth mounting" D "altazimuth mounting" BT telescope_mounting RT altitude_angle azimuth equatorial_mounting horizon_coordinate_system siderostat vertical_circle ## altimeter altimeter D "altimeter" BT measuring_instrument RT weather_station ## altimetry altimetry D "altimetry" ## altitude_angle altitude_angle ALT "elevation angle" D "altitude [angle]" RT altazimuth_mounting azimuth horizon horizon_coordinate_system sextant zenith_distance N "use for angle; see ALTITUDE_HEIGHT for height" ## aluminizing aluminizing D "aluminizing" RT aluminum_coating mirror vacuum_technique ## aluminum aluminum ALT "Al" D "aluminum (atomic number 13)" BT fundamental_chemical_element NT aluminum_coating HN "FVH: new (2007-OCT-25)" ## aluminum_coating aluminum_coating D "aluminium coating" UK "aluminum coating" BT aluminum coating thin_film RT aluminizing mirror optical_surface silver_coating vacuum_technique vapor_deposition CN "FVH: moved aluminium_coating to localized D (2007-SEP-24)" ## amateur_astronomy amateur_astronomy D "amateur astronomy" BT astronomy RT astronomer astronomical_research ## AM_Canum_Venaticorum_star AM_Canum_Venaticorum_star D "AM Canum Venaticorum star" BT hydrogen_deficient_star nova-like_variable RT UX_Ursae_Majoris_star dwarf_nova ## americium americium ALT "Am" D "americium (atomic number 95)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## AM_Herculis_star AM_Herculis_star ALT "polars" D "AM Herculis star" BT cataclysmic_variable_star ## ammonia ammonia D "ammonia" BT interstellar_molecule ## Amor_group Amor_group D "Amor group" BT minor_planet_family RT Apollo_group Trojan_group ## amplifier amplifier D "amplifier" BT instrument NT microchannel_plate parametric_amplifier preamplifier RT image_tube photomultiplier_tube pulse_counter pulse_counting ## amplitude amplitude D "amplitude" RT decay_oscillation magnitude oscillation pulsation variable_star vibration ## Am_star Am_star D "Am star" BT A_star magnetic_star magnetic_variable_star metal-rich_star NT spectrum_variable_star ## analog_recorder analog_recorder D "analog recorder" BT data_storage ## analysis analysis D "analysis" NT data_analysis fine_analysis signal_analysis signal_processing RT astronomical_technique quantization reduction_method N "combine with other terms" ## anemometer anemometer D "anemometer" BT measuring_instrument RT weather_station wind_vane HN "FVH: new (2007-SEP-21)" ## angular_diameter angular_diameter ALT "apparent diameter" D "angular diameter" BT diameter NT isophotal_diameter RT interferometry occultation speckle_interferometry ## angular_momentum angular_momentum D "angular momentum" RT kinematics momentum rotation ## angular_resolution angular_resolution D "angular resolution" BT resolution RT angular_separation beamwidth optics speckle_interferometry ## angular_separation angular_separation ALT "angular distance" D "angular separation" RT angular_resolution optical_double_star speckle_interferometry ## angular_velocity angular_velocity D "angular velocity" BT velocity RT celestial_mechanics orbital_velocity rotation ## anisotropy anisotropy D "anisotropy" RT background_radiation isotropy polarization_charge_separation ## annual_equation annual_equation D "annual equation" RT Earth-Moon_system Earth_orbit elliptical_orbit ## annual_parallax annual_parallax ALT "heliocentric parallax" "parallax" D "annual parallax" BT parallax RT Astronomical_Unit ## annular_eclipse annular_eclipse D "annular eclipse" BT eclipse RT total_eclipse ## anomaly anomaly D "anomaly" NT CNO_anomaly gravity_anomaly magnetic_anomaly CN "FVH: generic non-orbital anomaly; old entry moved to orbital_anomaly (2007-OCT-29)" ## anomalistic_month anomalistic_month D "anomalistic month" RT Moon orbital_anomaly ## anomalistic_year anomalistic_year D "anomalistic year" BT year RT orbital_anomaly ## ansa ansa D "ansa" RT lenticular_galaxy planetary_nebula ring ## antapex antapex D "antapex" RT apex solar_motion ## antarctic_observatory antarctic_observatory D "antarctic observatory" BT observatory ## antenna_design antenna_design D "antenna design" RT polar_diagram radio_telescope ## antenna antenna ALT "aerials" "antennas" D "antenna" BT radar_equipment NT Cassegrain_antenna Mills_cross_antenna Yagi_antenna dipole_antenna directional_antenna horn_antenna lens_antenna microwave_antenna parabolic_antenna radio_antenna reflector_antenna RT array current_sheet current dish_antenna feed_horn interferometer radar radio_telescope telescope ## anthropic_principle anthropic_principle D "anthropic principle" RT cosmology life ## antimatter antimatter D "antimatter" BT matter NT antiparticle ## antimony antimony ALT "Sb" D "antimony (atomic number 51)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## antineutrino antineutrino D "antineutrino" BT antiparticle RT neutrino ## antinode antinode D "antinode" RT vibration ## antinucleon antinucleon D "antinucleon" BT antiparticle ## antiparticle antiparticle D "antiparticle" BT antimatter elementary_particle NT antineutrino antinucleon antiproton positron ## antiproton antiproton D "antiproton" BT antiparticle RT proton ## antireflection_coating antireflection_coating D "antireflection coating" BT coating optical_film thin_film RT lens optical_surface ## apastron apastron D "apastron" BT apsis RT periastron ## aperiodic_comet aperiodic_comet D "aperiodic comet" BT comet ## aperture aperture D "aperture" RT aperture_synthesis apodization optical_system ## aperture_synthesis aperture_synthesis ALT "synthetic aperture" D "aperture synthesis" RT aperture grading_function grating_ring interferometry visibility_function ## apex apex D "apex" RT antapex solar_motion ## aphelion aphelion D "aphelion" BT apsis RT Earth_orbit perihelion planet ## apocenter apocenter D "apocenter" RT binary_star ## apodization apodization ALT "apodisation UK" D "apodization" RT aperture radio_telescope ## apogee apogee D "apogee" BT apsis RT Moon perigee ## Apollo_group Apollo_group D "Apollo group" BT minor_planet_family RT Amor_group Hirayama_family Trojan_group ## apparent_intensity apparent_intensity D "apparent intensity" BT intensity ## apparent_magnitude apparent_magnitude D "apparent magnitude" BT magnitude NT B_magnitude H_magnitude I_magnitude J_magnitude K_magnitude L_magnitude M_magnitude N_magnitude O_magnitude P_magnitude Q_magnitude R_magnitude U_magnitude V_magnitude photoelectric_magnitude photographic_magnitude photovisual_magnitude RT photometric_system photometry ## apparent_position apparent_position ALT "apparent places" D "apparent position" BT position RT astrometry true_position ## apparent_superluminal_motion apparent_superluminal_motion ALT "superluminal motion" D "apparent superluminal motion" BT motion RT velocity_of_light ## apsidal_motion apsidal_motion D "apsidal motion" BT motion RT apsis orbit ## apsis apsis ALT "apse" D "apsis" BT orbital_element NT apastron aphelion apogee periastron perigee perihelion RT apsidal_motion orbit N "apse = apsis, apsides is plural" ## Ap_star Ap_star ALT "peculiar A star" D "Ap star" BT A_star peculiar_star NT holmium_star manganese_star silicon_star spectrum_variable_star RT alpha2_Canum_Venaticorum_star magnetic_star magnetic_variable_star oblique_rotator rapid_oscillation ## archaeoastronomy archaeoastronomy ALT "ancient astronomy" "astroarchaeology" D "archaeoastronomy" BT astronomy history_of_astronomy NT megalithic_astronomy RT armillary_sphere astrolabe astrology ## arc arc D "arc" NT auroral_arc luminous_arc CN "FVH: made general term (2007-OCT-1)" ## argon argon ALT "Ar" D "argon (atomic number 18)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## armillary_sphere armillary_sphere D "armillary sphere" BT instrument RT archaeoastronomy ## array_processor array_processor D "array processor" BT computer RT detector_array ## array array D "array" NT detector_array diode_array phased_array t_array telescope_array very_long_baseline_interferometer y_array RT antenna grating_response interferometer radio_interferometer radio_telescope ## arsenic arsenic ALT "As" D "arsenic (atomic number 33)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## artificial_satellite artificial_satellite D "artificial satellite" NT geostationary_satellite space_observatory RT polar_orbit satellite_laser_ranging space_astronomy space_telescope space_vehicle ## ascending_node ascending_node D "ascending node" BT node CN "FVH: moved NODES to BT (2007-OCT-1)" ## ashen_light ashen_light D "ashen light" BT atmospheric_radiation RT Venus airglow N "refers to Venus' atmosphere" ## A_star A_star D "A star" BT early-type_star NT A_dwarf A_giant A_subdwarf A_subgiant A_supergiant Ae_star Am_star Ap_star RT early-type_variable_star spectral_type ## astatine astatine ALT "At" D "astatine (atomic number 85)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## asteroid_belt asteroid_belt D "asteroid belt" RT asteroid ## asteroid_occultation asteroid_occultation D "occultation by asteroid" BT occultation RT asteroid HN "FVH: new (2007-OCT-8)" ## asteroid asteroid ALT "minor planet" "planetoid" D "asteroid" BT rotating_body NT near-Earth_asteroid RT Edgeworth-Kuiper_belt Kirkwood_gap Solar_System asteroid_belt asteroid_occultation interplanetary_matter meteor_stream meteorite meteoroid_dust_cloud meteoroid minor_planet_family planetesimal resonance_gap trans-Neptunian_object ## asteroseismology asteroseismology ALT "stellar seismology" D "asteroseismology" BT seismology NT helioseismology RT pulsating_variable_star pulsation rapid_oscillation solar_oscillation stellar_oscillation ## astigmatism astigmatism D "astigmatism" BT optical_aberration RT chromatic_aberration comatic_aberration distortion field_curvature spherical_aberration ## astrobiology astrobiology ALT "exobiology" D "astrobiology" BT astronomy biology scientific_field RT cosmochemistry extraterrestrial_life ## astrodynamics astrodynamics D "astrodynamics" RT celestial_mechanics ## astrographic_camera astrographic_camera D "astrographic camera" BT camera ## astrographic_catalog astrographic_catalog ALT "astrographic catalogues UK" D "astrographic catalog" BT catalog ## astrograph astrograph D "astrograph" BT astrometric_instrument ## astrolabe astrolabe D "astrolabe" BT astrometric_instrument instrument NT Danjon_astrolabe impersonal_astrolabe RT archaeoastronomy ## astrology astrology D "astrology" BT scientific_field RT archaeoastronomy astronomy constellation planet zodiac ## astrometric_binary_star astrometric_binary_star D "astrometric binary star" BT binary_star ## astrometric_instrument astrometric_instrument D "astrometric instrument" BT instrument NT astrograph astrolabe quadrant sextant transit_instrument RT astrometry time ## astrometry astrometry ALT "positional astronomy" D "astrometry" BT astronomical_technique astronomy observing_technique NT photographic_astrometry radio_astrometry space_astrometry RT Earth_rotation aberration apparent_position astrometric_instrument astronomical_geodesy celestial_mechanics coordinate_system equator_position fundamental_star latitude_determination meridian_circle optical_position parallax precession reference_system stellar_motion transit_instrument transit true_position ## astronomer astronomer D "astronomer" RT amateur_astronomy astronomical_research ## astronomical_constant astronomical_constant D "astronomical constant" BT constant NT Astronomical_Unit Oort_constant RT celestial_mechanics physical_constant ## astronomical_geodesy astronomical_geodesy D "astronomical geodesy" BT geodesy RT astrometry ## astronomical_optics astronomical_optics D "astronomical optics" BT optics ## astronomical_research astronomical_research D "astronomical research" NT space_research RT amateur_astronomy astronomer ## astronomical_technique astronomical_technique D "astronomical technique" NT astrometry interferometry photometry polarimetry spectrophotometry spectroscopy RT analysis observing_technique photography reduction_method N "most used in several wavelength region" ## Astronomical_Unit Astronomical_Unit ALT "A.U." "AU" D "Astronomical Unit" BT astronomical_constant RT annual_parallax distance_scale heliocentric_correction parallax parsec solar_parallax trigonometric_parallax CN "FVH: added ALT A.U. (2007-09-21)" ## astronomy astronomy D "astronomy" BT scientific_field NT amateur_astronomy archaeoastronomy astrobiology astrometry cosmic_ray_astronomy cosmogony cosmology ground-based_astronomy infrared_astronomy space_astronomy RT astrology ## astrophysics astrophysics D "astrophysics" BT scientific_field NT high-energy_astrophysics theoretical_astrophysics RT cosmology CN "FVH: moved theoretical_astrophysics to NT (2007-OCT-1)" N "combine with other terms" ## A_subdwarf A_subdwarf D "A subdwarf star" BT A_star subdwarf RT A_dwarf ## A_subgiant A_subgiant D "A subgiant star" BT A_star subgiant ## A_supergiant A_supergiant D "A supergiant star" BT A_star early-type_supergiant supergiant ## asymptotic_giant_branch asymptotic_giant_branch ALT "AGB" D "asymptotic giant branch" RT Hertzsprung-Russell_diagram late-type_giant post-asymptotic_giant_branch ## ataxite ataxite D "ataxite" BT meteorite ## atlas atlas ALT "chart" D "atlas" NT star_atlas RT catalog finding_chart map sky_survey survey ## atmosphere atmosphere D "atmosphere" NT Earth_atmosphere stellar_atmosphere RT aeronomy air boundary_layer greenhouse_effect limb_brightening limb_darkening macroturbulence microturbulence opacity planet radiation_belt refraction_angle scale_height scintillation temperature_zone water_vapor N "combine with other terms" ## atmospheric_density atmospheric_density D "atmospheric density" BT density RT scale_height ## atmospheric_extinction atmospheric_extinction ALT "extinction" D "atmospheric extinction" BT absorption scattering RT Earth_atmosphere absorption_coefficient atmospheric_window light_absorption light_scattering ultraviolet_extinction N "refers to Earth atmosphere" ## atmospheric_radiation atmospheric_radiation ALT "sky radiation" D "atmospheric radiation" NT afterglow airglow ashen_light aurora terrestrial_radiation RT sky_brightness N "ES: moved terrestrial_radiation from BT to NT (2007-OCT-8)" ## atmospheric_refraction atmospheric_refraction D "atmospheric refraction" RT active_optics adaptive_optics atmospheric_scintillation point_spread_function refractive_index scintillation seeing speckle ## atmospheric_scattering atmospheric_scattering D "atmospheric scattering" RT Earth_atmosphere absorption ## atmospheric_scintillation atmospheric_scintillation ALT "twinkling" D "atmospheric scintillation" BT scintillation RT Earth_atmosphere atmospheric_refraction seeing ## atmospheric_tide atmospheric_tide D "atmospheric tide" BT tide ## atmospheric_window atmospheric_window D "atmospheric window" BT window NT infrared_transmission_window optical_transmission_window radio_transmission_window RT Earth_atmosphere absorption atmospheric_extinction transparency N "spectral ranges transmitted by the Earth's atmosphere" ## atomic_clock atomic_clock ALT "caesium clock" "cesium clock" D "atomic clock" BT clock measuring_instrument RT atomic_time geodesy time time_standard time_synchronization very_long_baseline_interferometry ## atomic_line atomic_line D "atomic line" RT atomic_spectrum ## atomic_physics atomic_physics D "atomic physics" BT scientific_field ## atomic_process atomic_process D "atomic process" RT absorption_line emission_line equation_of_state excitation population_inversion ## atomic_spectrum atomic_spectrum D "atomic spectrum" BT absorption_spectrum spectrum RT atomic_line ## atomic_time atomic_time D "atomic time" RT atomic_clock ## atom atom D "atom" BT matter NT fundamental_chemical_element RT chemical_element ## attenuation attenuation D "attenuation" RT filter neutral_density_filter ## auroral_arc auroral_arc D "auroral arc" BT arc aurora ## auroral_jet auroral_jet D "auroral jet" BT aurora ## aurora aurora D "aurora" BT atmospheric_radiation NT auroral_arc auroral_jet RT Rayleigh airglow light_emission magnetic_disturbances magnetic_pole magnetic_storm night_sky_brightness photoionization sky_brightness solar_activity upper_atmosphere ## australite australite D "australite" BT meteorite tektite RT bediasite chondrite moldavite ## auto-correlation auto-correlation ALT "autocorrelation" D "auto-correlation" BT correlation RT cross-correlation data_processing HN "FVH: new (2007-NOV-1)" ## autoguider autoguider D "autoguider" BT control_system guide_system RT automatic_patrol_telescope quadrant_detector tracking ## automated_telescope automated_telescope ALT "robotic telescope" D "automated telescope" BT telescope NT automatic_patrol_telescope RT remote_control_system ## automatic_patrol_telescope automatic_patrol_telescope D "automatic patrol telescope" BT automated_telescope optical_telescope RT autoguider photometry remote_control_system ## autumnal_equinox autumnal_equinox D "autumnal equinox" BT equinox RT vernal_equinox ## auxiliary_instrument auxiliary_instrument D "auxiliary instrument" BT instrument ## avalanche_photodiode avalanche_photodiode D "avalanche photodiode" BT photodiode photoelectronic_device RT photometry ## axial_ratio axial_ratio D "axial ratio" BT ratio RT axis major_axis minor_axis HN "ES: new (2007-OCT-11)" ## axion axion D "axion" BT elementary_particle ## axis axis D "axis" RT axial_ratio N "combine with other terms" ## azimuth azimuth ALT "bearing" D "azimuth" RT altazimuth_mounting altitude_angle horizon horizon_coordinate_system ## Baade-Wesselink_method Baade-Wesselink_method D "Baade-Wesselink method" RT Cepheid diameter ## background background D "background" N "combine with other terms" ## background_noise background_noise D "background noise" BT noise RT cosmic_noise signal-to-noise_ratio sky_noise ## background_radiation background_radiation ALT "radiation background" D "background radiation" BT radiation NT X-ray_background cosmic_background_radiation cosmic_ray gamma-ray_background microwave_background radio_background ultraviolet_background RT Sunyaev-Zeldovich_effect anisotropy cosmic_noise sky_brightness ## Bailey_type Bailey_type ALT "AB variable star" D "Bailey type" BT RR_Lyrae_star ## bailys_bead bailys_bead D "Baily's bead" RT Sun diamond_ring_effect solar_eclipse ## Baker-Nunn_camera Baker-Nunn_camera D "Baker-Nunn camera" BT catadioptric_system meteor_camera reflecting_telescope wide-field_telescope RT Bouwers_telescope Schmidt_telescope ## balloon-borne_instrument balloon-borne_instrument ALT "balloon borne instrument" D "balloon-borne instrument" RT X-ray_astronomy airplane-borne_instrument cosmic_ray_astronomy gamma-ray_astronomy ground-based_astronomy rocket-borne_instrument satellite-borne_instrument space_probe_instrument space_telescope ultraviolet_astronomy ## Balmer_continuum Balmer_continuum D "Balmer continuum" BT hydrogen_spectrum RT Balmer_series ## Balmer_limit Balmer_limit D "Balmer limit" BT Balmer_series ## Balmer_series Balmer_series ALT "Balmer line" D "Balmer series" BT hydrogen_spectrum NT H_alpha H_beta H_delta H_epsilon H_gamma Balmer_limit RT absorption_spectrum Balmer_continuum Brackett_series Lyman_series Paschen_series Pfund_series ## barium barium ALT "Ba" D "barium (atomic number 56)" BT fundamental_chemical_element RT barium_star HN "FVH: new (2007-OCT-25)" ## barium_star barium_star ALT "Ba II star" D "barium star" BT star NT semi-barium_star RT S_star barium heavy_metal_star ## barometer barometer D "barometer" BT measuring_instrument RT pressure weather_station HN "FVH: new (2007-SEP-21)" ## barred_spiral_galaxy barred_spiral_galaxy D "barred spiral galaxy" BT galaxy spiral_galaxy NT B_galaxy ## baryonic_Dark_Matter baryonic_Dark_Matter D "baryonic Dark Matter" BT Dark_Matter RT cold_Dark_Matter ## baryon baryon D "baryon" BT elementary_particle RT Omega_baryon quark ## basin basin D "basin" RT crater ## B_band B_band D "B band" BT Fraunhofer_line molecular_band RT molecular_spectrum ## B_dwarf B_dwarf D "B dwarf star" BT B_star dwarf NT gamma_Cassiopeiae_star ## beam_switching beam_switching D "beam switching" RT radio_telescope ## beam_waveguide beam_waveguide D "beam waveguide" RT collimator ## beamwidth beamwidth D "beamwidth" RT angular_resolution polar_diagram radio_telescope ## bediasite bediasite D "bediasite" BT meteorite tektite RT australite chondrite moldavite ## berkelium berkelium ALT "Bk" D "berkelium (atomic number 97)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## beryllium beryllium ALT "Be" D "beryllium (atomic number 4)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Besselian_epoch Besselian_epoch D "Besselian epoch" BT epoch standard_epoch RT Julian_epoch time ## Bessel_photometry Bessel_photometry ALT "Bessel UBVRI photometry" D "Bessel photometry" BT broad_band_photometry photometric_system RT BV_photometry B_magnitude I_magnitude Johnson_photometry R_magnitude U_magnitude V_magnitude HN "FVH: new (2007-SEP-21)" ## Be_star Be_star ALT "Be dwarf star" D "Be star" BT B_star Herbig_AeBe_star early-type_emission_star NT Herbig_AeBe_star lambda_eridani_star RT Ae_star circumstellar_shell CN "FVH: moved Be_dwarf to ALT and U Herbig_star to BT HERBIG_AeBe_STARS (2007-OCT-1)" ## beta_Cephei_star beta_Cephei_star ALT "beta Canis Majoris star" D "beta Cephei star" BT early-type_variable_star multi-periodic_variable_star pulsating_variable_star short_period_variable_star RT non-radial_pulsation radial_pulsation ## beta_Lyrae_star beta_Lyrae_star D "beta Lyrae star" BT close_binary_star contact_binary_star eclipsing_binary_star ellipsoidal_variable_star ## B_galaxy B_galaxy D "barred galaxy (Yerkes classification scheme)" BT barred_spiral_galaxy RT Yerkes_classification HN "FVH+AG: new (2007-OCT-26)" ## B_giant B_giant D "B giant star" BT B_star giant ## Bianchi_cosmology Bianchi_cosmology D "Bianchi cosmology" BT cosmology ## bias_calibration bias_calibration D "bias calibration" BT calibration RT CCD_detector HN "FVH: new (2007-OCT-3)" ## Big_Bang_theory Big_Bang_theory D "Big Bang theory" BT cosmology RT Friedmann_universe Hubble_radius Hubble_time Lemaitre_universe closed_universe early_universe hadron_barrier open_universe primordial_fireball relativistic_velocity steady-state_theory ## binary_pulsar binary_pulsar D "binary pulsar" BT pulsar ## binary_star binary_star ALT "binaries" "double star" D "binary star" BT binary_system star NT Algol_variable_star RS_Canum_Venaticorum_star astrometric_binary_star close_binary_star contact_binary_star detached_binary_star eclipsing_binary_star ellipsoidal_variable_star eruptive_binary_star interacting_binary_star semi-detached_binary_star spectroscopic_binary_star visual_binary_star wide_binary_star RT accretion apocenter center_of_mass companion_star dynamical_parallax inclination mass-loss mass-ratio multiple_star occultation orbit_determination orbit period period_change period_determination phase_wave position_angle runaway_star semimajor_axis separation two-body_problem von_Zeipel_theorem N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## binary_system binary_system D "binary system" NT binary_star double_galaxy ## biology biology D "biology" BT scientific_field NT astrobiology space_biology ## bipolar_galaxy bipolar_galaxy D "bipolar galaxy" BT galaxy ## bipolar_group bipolar_group D "bipolar group" BT sunspot_group RT sunspot ## bipolar_nebula bipolar_nebula D "bipolar nebula" BT nebula RT bipolar_outflow ## bipolar_outflow bipolar_outflow ALT "bipolar flow" D "bipolar outflow" BT mass-loss RT bipolar_nebula circumstellar_matter radio_source radio_structure ## birth_rate birth_rate D "birth rate" RT mass_function protostar star_formation stellar_evolution ## bismuth bismuth ALT "Bi" D "bismuth (atomic number 83)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## black_body_radiation black_body_radiation ALT "thermal black body radiation" D "black body radiation" BT electromagnetic_radiation RT brightness_temperature emissivity thermal_radiation ultraviolet_radiation ## black_dwarf black_dwarf D "black dwarf star" BT dwarf low-mass_star stellar_object RT white_dwarf ## black_hole black_hole D "black hole" BT collapsed_star compact_object degenerate_matter relativistic_star NT Kerr_black_hole stellar_black_hole RT Hawking_radiation Kruskal_diagram Penrose_process Schwarzschild_radius X-ray_binary_star accretion_disk ergosphere event_horizon galactic_nucleus gravitational_collapse gravitational_lensing massive_object naked_singularity relativistic_astrophysics space-time_singularity supernova_remnant white_hole ## blank_field blank_field D "blank field" RT galaxy_void ## blazar blazar D "blazar" BT active_galactic_nucleus RT BL_Lacertae_object quasar ## Blazhko_effect Blazhko_effect D "Blazhko effect" RT RR_Lyrae_star ## BL_Herculis_star BL_Herculis_star D "BL Herculis star" BT W_Virginis_star pulsating_variable_star RT Cepheid RR_Lyrae_star radial_pulsation ## blink_comparator blink_comparator D "blink comparator" BT instrument ## blinking blinking D "blinking" N "combine with other terms" ## BL_Lacertae_object BL_Lacertae_object ALT "BL Lac object" D "BL Lacertae object" BT compact_object extragalactic_radio_source galaxy variable_source RT Seyfert_galaxy active_galactic_nucleus blazar compact_galaxy quasar ## blue_galaxy blue_galaxy D "blue galaxy" BT blue_object galaxy ## blue_loop blue_loop D "blue loop" BT giant_branch HN "ES: new (2007-OCT-8)" ## blue_object blue_object D "blue object" NT blue_galaxy ## blueshift blueshift ALT "blue shift" "blue-shift" D "blueshift" BT Doppler_effect line_shift RT frequency_shift ## blue_straggler_star blue_straggler_star D "blue straggler star" BT main_sequence_star young_star RT open_star_cluster ## B_magnitude B_magnitude D "B magnitude" BT apparent_magnitude RT Bessel_photometry Johnson_photometry ## Bodes_law Bodes_law ALT "Titius-Bode law" D "Bode's law" RT Solar_System distance planet ## bohrium bohrium ALT "Bh" D "bohrium (atomic number 107)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Bok_globule Bok_globule D "Bok globule" BT dark_nebula globule interstellar_matter RT H_II_region cometary_globule protostar star_formation ## bolide bolide D "bolide" BT meteor RT fireball ## bolometer bolometer D "bolometer" BT instrument RT bolometric_correction photometer radiation radiometer ## bolometric_correction bolometric_correction D "bolometric correction" RT bolometer ## boron boron ALT "B" D "boron (atomic number 5)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Bose-Einstein_nucleus Bose-Einstein_nucleus D "Bose-Einstein nucleus" BT nucleus_atom RT Bose-Einstein_statistics Fermi-Dirac_nucleus ## Bose-Einstein_statistics Bose-Einstein_statistics D "Bose-Einstein statistics" RT Bose-Einstein_nucleus Fermi-Dirac_statistics boson ## boson boson D "boson" BT elementary_particle particle NT alpha_particle composite_particle meson photon pion RT Bose-Einstein_statistics fermion hadron lepton ## boundary_layer boundary_layer D "boundary layer" RT atmosphere planet ## bound-free_transition bound-free_transition ALT "bound free transition" D "bound-free transition" RT absorption_line absorption_spectrum ## Bouwers_telescope Bouwers_telescope D "Bouwers telescope" BT catadioptric_system reflecting_telescope RT Baker-Nunn_camera Maksutov_telescope wide-field_telescope ## bow_shock bow_shock D "bow-shock" BT shock_wave ## Bp_star Bp_star D "Bp star" BT B_star magnetic_star peculiar_star ## Brackett_series Brackett_series D "Brackett series" BT hydrogen_spectrum infrared_radiation RT Balmer_series Lyman_series Paschen_series Pfund_series ## bremsstrahlung bremsstrahlung ALT "free free transition" "free-free transition" D "bremsstrahlung" BT electromagnetic_radiation RT electron radiation_mechanism spectrum synchrotron_radiation ## bridge bridge D "bridge" N "between galaxy" ## bright_galaxy bright_galaxy D "bright galaxy" BT galaxy RT Local_Group nearby_galaxy ## bright_nebula bright_nebula D "bright nebula" BT nebula ## bright_point bright_point D "solar bright point" RT Sun HN "FVH: new (2007-OCT-29)" ## bright_star bright_star D "bright star" BT high-luminosity_star star RT brightness CN "FVH: correction from original IAU to reflect flux, not necessarily luminosity (2007-OCT-1)" ## brightness brightness D "brightness" BT optical_property NT surface_brightness RT bright_star illumination integration_time intensity luminosity magnitude ## brightness_distribution brightness_distribution D "brightness distribution" N "see luminosity distribution" ## brightness_temperature brightness_temperature D "brightness temperature" BT temperature RT black_body_radiation luminosity_distribution optical_property ## brillouin_scattering brillouin_scattering D "Brillouin scattering" RT Mie_scattering brillouin_spectrum ## brillouin_spectrum brillouin_spectrum D "Brillouin spectrum" BT spectrum RT brillouin_scattering light_scattering ## broad_band_photometry broad_band_photometry ALT "wide-band photometry" D "broad-band photometry" BT CCD_photometry photoelectric_photometry photographic_photometry NT Bessel_photometry BV_photometry Cape_photometry Cape_RI_photometry Gunn_photometry HST_photometry Johnson_photometry Kron-Cousins_photometry Sloan_photometry infrared_photometry rgb_photometry rgu_photometry two-color_photometry ultraviolet_photometry RT medium_band_photometry narrow_band_photometry CN "FVH: added BESSEL_PHOTOMETRY, GUNN_PHOTOMETRY, HST_PHOTOMETRY, KRON_COUSINS_PHOTOMETRY, SLOAN_PHOTOMETRY (2007-SEP-21)" ## bromine bromine ALT "Br" D "bromine (atomic number 35)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## brown_dwarf brown_dwarf D "brown dwarf" BT late-type_dwarf late-type_subdwarf stellar_object NT L_dwarf L_subdwarf T_dwarf T_subdwarf RT dwarf low-mass_star planetar ## B_star B_star D "B star" BT OB_star early-type_star young_star NT 53_Persei_star B_dwarf B_giant B_subdwarf B_supergiant Be_star Bp_star Bw_star mercury_manganese_star RT O_cluster early-type_variable_star spectral_type ## B_subdwarf B_subdwarf D "B subdwarf star" BT B_star subdwarf ## B_supergiant B_supergiant D "B supergiant star" BT B_star OB_supergiant early-type_supergiant supergiant ## bubble bubble D "bubble" NT interstellar_bubble ## bulge bulge D "bulge" NT Galactic_bulge RT galaxy_structure N "combine with other terms" ## Burkert_profile Burkert_profile D "Burkert mass-profile" BT mass_distribution RT Navarro-Frenk-White_profile exponential_profile isothermal_sphere HN "FVH: new (2007-OCT-5)" ## burster burster D "burster" RT X-ray_burst burst gamma-ray_burst optical_burst radio_burst ## burst burst D "burst" NT X-ray_burst gamma-ray_burst optical_burst outburst radio_burst rapid_burst RT burster flare ## butterfly_diagram butterfly_diagram D "butterfly diagram" RT solar_activity solar_cycle sunspot_cycle sunspot_number sunspot ## BV_photometry BV_photometry D "BV photometry" BT broad_band_photometry two-color_photometry RT Bessel_photometry Johnson_photometry CN "FVH: added NT BESSEL_PHOTOMETRY, moved TWO-COLOR to BT and JOHNSON to NT (2007-SEP-21)" ## Bw_star Bw_star D "Bw star" BT B_star helium-poor_star ## BY_Draconis_star BY_Draconis_star D "BY Draconis star" BT flare_star RT starspot ## cadmium cadmium ALT "Cd" D "cadmium (atomic number 48)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## caesium caesium ALT "Cs" "cesium" D "caesium (atomic number 55)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Ca_II_emission_line Ca_II_emission_line D "Ca II emission line" BT calcium_line emission_line metal_line RT Wilson-Bappu_effect ## calcium calcium ALT "Ca" D "calcium (atomic number 20)" BT fundamental_chemical_element RT calcium_line HN "FVH: new (2007-OCT-25)" ## calcium_line calcium_line D "calcium line" BT metal_line spectral_line NT Ca_II_emission_line H_and_K_line K_line RT absorption_line calcium ## calendar calendar D "calendar" NT Gregorian_calendar Julian_calendar RT ephemeris time ## calibration calibration D "calibration" NT bias_calibration dark-current_calibration dead-time_calibration linearity_calibration self-calibration_method RT comparison_lamp flat_field_lamp instrument lamp measuring_instrument reseaux N "combine with other terms" ## californium californium ALT "Cf" D "californium (atomic number 98)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## camera_lens camera_lens D "camera lens" BT lens RT camera ## camera camera D "camera" BT optical_instrument photographic_instrument NT Schmidt_camera all-sky_camera astrographic_camera ultraviolet_camera webcam RT all-sky_photography camera_lens coronagraph filter_wheel flat_field_lamp photograph photography shutter ultraviolet_photography wide-angle_lens N "photographic type only here" ## canyon canyon D "canyon" BT surface_of_celestial_body HN "FVH: new (2007-OCT-3)" ## Cape_photometry Cape_photometry ALT "UCBV photometry" D "Cape photometry" BT broad_band_photometry photometric_system RT Cape_RI_photometry Johnson_photometry Kapteyn_selected_area ## Cape_RI_photometry Cape_RI_photometry D "Cape RI photometry" BT broad_band_photometry RT Cape_photometry Johnson_photometry ## capture capture D "capture" RT absorption N "combine with other terms" ## carbonaceous_chondrite carbonaceous_chondrite D "carbonaceous chondrite" BT chondrite ## carbon_burning carbon_burning D "carbon burning" BT nuclear_fusion nucleosynthesis RT carbon carbon_flash giant helium_burning hydrogen_burning nuclear_reaction oxygen_burning shell_burning silicon_burning stellar_evolution stellar_interior ## carbon carbon ALT "C" D "carbon (atomic number 6)" BT fundamental_chemical_element RT carbon_burning carbon_compound carbon_nitrogen_cycle HN "FVH: new (2007-OCT-25)" ## carbon_compound carbon_compound D "carbon compound" BT interstellar_molecule NT CS carbon_dioxide carbon_disulfide carbon_monosulfide carbon_monoxide cyanoacetylene cyanodiacetylene cyanogen cyanopolyene hydrated_carbon RT carbon ## carbon_dioxide carbon_dioxide ALT "CO2" "CO_2" D "carbon dioxide" BT carbon_compound gas ## carbon_disulfide carbon_disulfide D "carbon disulfide" BT carbon_compound ## carbon_flash carbon_flash ALT "carbon detonation" D "carbon flash" RT carbon_burning helium_flash nuclear_fusion red_giant_tip ## carbon_line carbon_line D "carbon line" BT metal_line spectral_line NT C_I_emission ## carbon_monosulfide carbon_monosulfide ALT "CS" D "carbon monosulfide" BT carbon_compound ## carbon_monoxide carbon_monoxide ALT "CO" D "carbon monoxide" BT carbon_compound gas RT Swan_band ## carbon_nitrogen_cycle carbon_nitrogen_cycle ALT "CNO cycle" "carbon cycle" D "carbon nitrogen cycle" BT hydrogen_burning RT CNO_anomaly carbon nitrogen nuclear_fusion proton-proton_reaction stellar_interior ## carbon_star carbon_star ALT "C star" D "carbon star" BT late-type_giant RT CH_star CN_star R_star S_star Wolf-Rayet_star ## Cassegrain_antenna Cassegrain_antenna ALT "Cassegrain antennas" "two reflector antennas" "two-reflector antennas" D "Cassegrain antenna" BT antenna radio_telescope RT secondary_mirror subreflector ## Cassegrain_focus Cassegrain_focus D "Cassegrain focus" BT Cassegrain_telescope focus RT Coude_focus Nasmyth_focus Newtonian_focus parabolic_antenna prime_focus secondary_mirror subreflector ## Cassegrain_telescope Cassegrain_telescope D "Cassegrain telescope" BT telescope NT Cassegrain_focus ## cataclysmic_variable_star cataclysmic_variable_star ALT "CV" "cataclysmic binary star" "eruptive variable star" D "cataclysmic variable star" BT X-ray_binary_star close_binary_star eruptive_binary_star interacting_binary_star variable_star NT AM_Herculis_star SX_Arietis_star UV_Persei_star dwarf_nova nova-like_variable classical_nova RT eruption low-mass_X-ray_binary_star mass_exchange mass-loss optical_outburst supernova symbiotic_star white_dwarf ## catadioptric_system catadioptric_system D "catadioptric system" BT optical_system NT Baker-Nunn_camera Bouwers_telescope Maksutov_telescope Schmidt_telescope RT corrector_plate field_corrector lens mirror optical_telescope ## catalog catalog ALT "catalogues UK" D "catalog" NT Henry_Draper_catalog astrographic_catalog radio_source_catalog RT FK_catalog_system atlas ephemeris finding_list fundamental_star map nomenclature sky_survey survey ultraviolet_survey N "e.g. radio, star, x ray, etc.; combine with other terms" ## catastrophe_theory catastrophe_theory D "catastrophe theory" RT mathematical_analysis ## cathode cathode D "cathode" BT electrode NT photocathode RT photomultiplier_tube quantum_efficiency thermionic_emission ## catoptric_system catoptric_system D "catoptric system" BT optical_system RT mirror optical_telescope ## caustic_crossing caustic_crossing D "caustic crossing" RT caustic cusp_crossing cusp gravitational_lensing HN "FVH: new (2007-OCT-8)" ## caustic caustic D "caustic" RT caustic_crossing cusp_crossing gravitational_lensing HN "FVH: new (2007-OCT-8)" ## CCD_detector CCD_detector ALT "CCD camera" D "CCD detector" BT multi-channel_detector two-dimensional_detector RT CCD_observation CCD_photometry bias_calibration charge-coupled_device dark-current_calibration photometer television_detector ## CCD_observation CCD_observation D "CCD observation" BT observation RT CCD_detector CCD_photometry charge-coupled_device ## CCD_photometry CCD_photometry D "CCD photometry" BT photometry NT broad_band_photometry medium_band_photometry narrow_band_photometry RT CCD_detector CCD_observation charge-coupled_device photoelectric_photometry photographic_photometry ## cD_galaxy cD_galaxy D "cD galaxy (compact D galaxy in the Yerkes classification scheme)" BT D_galaxy elliptical_galaxy giant_galaxy massive_galaxy RT Yerkes_classification galaxy_cluster giant_radio_galaxy nucleus_celestial_object ## celestial_coordinate_system celestial_coordinate_system D "celestial coordinate system" BT coordinate_system NT Galactic_coordinate_system ecliptic_coordinate_system equatorial_coordinate_system supergalactic_coordinate_system HN "FVH: new (2007-NOV-2)" ## celestial_equator celestial_equator D "celestial equator" BT equatorial_coordinate_system RT Declination Right_Ascension celestial_pole celestial_sphere equator_correction equator_determination equator_position equinox obliquity_of_ecliptic ## celestial_mechanics celestial_mechanics D "celestial mechanics" BT scientific_field RT Keplerian_orbit Lagrangian_point N-body_problem angular_velocity astrodynamics astrometry astronomical_constant gravitation gravitational_wave lunar_theory orbital_element orbital_evolution orbital_motion orbital_theory orbit osculatory_element perturbation perturbation_theory planetary_alignment planetary_theory precession three-body_problem two-body_problem ## celestial_pole celestial_pole D "celestial pole" BT equatorial_coordinate_system pole NT North_Celestial_Pole South_Celestial_Pole RT celestial_equator celestial_sphere equator polar_axis ## celestial_sphere celestial_sphere D "celestial sphere" RT celestial_equator celestial_pole horizon meridian zenith ## celsius_temperature_scale celsius_temperature_scale D "Celsius temperature scale" BT temperature_scale RT Kelvin absolute_temperature_scale temperature ## center center D "center" N "combine with other terms" ## center_of_mass center_of_mass D "center of mass" BT orbital_element RT binary_star pericenter planet ## central_star central_star D "central star" BT star RT planetary_nebula ## centrifugal_force centrifugal_force D "centrifugal force" BT force RT centripetal_force ## centripetal_force centripetal_force D "centripetal force" BT force RT centrifugal_force ## Cepheid_distance Cepheid_distance D "Cepheid distance" BT distance_measurement RT Cepheid HN "ES: new (2007-OCT-8)" ## Cepheid Cepheid ALT "Cepheid variable star" "bump Cepheid" "classical Cepheid" "delta Cephei star" D "Cepheid" BT pulsating_variable_star NT double-mode_Cepheid young_disk_Cepheid RT Baade-Wesselink_method BL_Herculis_star Cepheid_distance He_II_ionization_zone RR_Lyrae_star W_Virginis_star dwarf_Cepheid instability_strip kappa_mechanism period-age_relation period-color_relation period-luminosity-color_relation period-luminosity_relation period-radius_relation period-spectrum_relation radial_pulsation radius-luminosity_relation N "most commonly used term" ## Cerenkov_counter Cerenkov_counter ALT "Cherenkov counter" D "Cerenkov counter" BT scintillation_counter RT Cerenkov_radiation cosmic_ray N "American spelling" ## Cerenkov_radiation Cerenkov_radiation ALT "Cerenkov effect" D "Cerenkov radiation" BT electromagnetic_radiation radiation RT Cerenkov_counter cosmic_ray gamma-ray_radiation nuclear_radiation radiation_mechanism ultraviolet_radiation N "American spelling" ## Ceres Ceres D "Ceres" BT dwarf_planet RT Solar_System HN "FVH: new (2007-OCT-2)" ## cerium cerium ALT "Ce" D "cerium (atomic number 58)" BT fundamental_chemical_element rare_earth HN "FVH: new (2007-OCT-25)" ## Chandler_wobble Chandler_wobble ALT "polar wandering" D "Chandler wobble" RT Earth_rotation latitude_determination latitude_variation polar_motion ## Chandrasekhar_mass Chandrasekhar_mass D "Chandrasekhar limit" "Chandrasekhar limit; the mass-limit for a degenerate stellar object" BT mass RT gravitational_collapse hydrogen_burning mass-radius_relation stellar_interior white_dwarf ## Chandrasekhar-Schoenberg_limit Chandrasekhar-Schoenberg_limit ALT "Chandrasekhar-Schonberg limit" "Schoenberg-Chandrasekhar limit" "Schonberg-Chandrasekhar limit" D "Chandrasekhar-Schoenberg limit; the mass-limit for an isothermal stellar core" BT mass RT gravitational_collapse hydrogen_burning mass-radius_relation stellar_interior ## charge-coupled_device charge-coupled_device ALT "CCD" "charge coupled device" D "charge-coupled device" BT photoelectronic_device semiconductor_device RT CCD_detector CCD_observation CCD_photometry detector multi-channel_detector quantum_efficiency read_out_noise two-dimensional_detector CN "FVH: added RT READ_OUT_NOISE (2007-SEP-21)" N "use abbreviated form (CCD) when combined with other terms" ## charge-injection_device charge-injection_device ALT "CID" "charge injection device" D "charge-injection device" BT photoelectronic_device semiconductor_device RT detector two-dimensional_detector ## charge-transfer_device charge-transfer_device ALT "CCD" "charge transfer device" D "charge-transfer device" BT photoelectronic_device semiconductor_device RT detector two-dimensional_detector ## chemical_composition chemical_composition D "chemical composition" RT abundance peculiar_star ## chemical_element chemical_element D "chemical element" NT fundamental_chemical_element heavy_element isotope trace_element RT abundance atom curve_of_growth element_formation metal_abundance origin N "see appendix" ## chemical_evolution chemical_evolution D "chemical evolution" NT enrichment RT abundance stellar_evolution ## chemiluminescence chemiluminescence D "chemiluminescence" BT luminescence RT light_emission ## chemistry chemistry D "chemistry" BT scientific_field NT cosmochemistry ## chlorine chlorine ALT "Cl" D "chlorine (atomic number 17)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## chondrite chondrite D "chondrite" BT meteorite NT achondrite carbonaceous_chondrite chondrules RT australite bediasite moldavite ## chondrules chondrules D "chondrules" BT chondrite ## chromatic_aberration chromatic_aberration D "chromatic aberration" BT optical_aberration RT astigmatism comatic_aberration distortion field_curvature optical_system spherical_aberration ## chromium chromium ALT "Cr" D "chromium (atomic number 24)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## chromosphere chromosphere D "chromosphere" RT Sun coronal_loop facula fibrill flash_spectrum macro_spicule mottle photosphere plage prominence quiescent_prominence solar_atmosphere solar_filament spicule stellar_atmosphere stellar_wind transition_region ## chronometer chronometer ALT "chronograph" D "chronometer" BT clock measuring_instrument RT time ## CH_star CH_star D "CH star" BT giant RT carbon_star ## C_I_emission C_I_emission D "C I emission" BT carbon_line emission_spectrum ## C_II_region C_II_region D "C II region" BT interstellar_matter RT dark_cloud ## circular_orbit circular_orbit D "circular orbit" BT elliptical_orbit RT hyperbolic_orbit orbital_motion parabolic_orbit ## circular_polarization circular_polarization ALT "circular polarisation UK" D "circular polarization" BT light_polarization RT plane_polarization quarter_wave_plate CN "FVH: added RT QUARTER_WAVE_PLATES (2007-SEP-21)" ## circumplanetary_matter circumplanetary_matter D "circumplanetary matter" BT matter RT circumstellar_matter ## circumstellar_disk circumstellar_disk D "circumstellar discs" UK "circumstellar disk" BT disk rotating_body RT accretion_disk circumstellar_gas circumstellar_matter mass-loss torus ## circumstellar_dust circumstellar_dust D "circumstellar dust" BT circumstellar_grain circumstellar_matter RT R_Coronae_Borealis_star circumstellar_gas cocoon_star dust_shell ## circumstellar_envelope circumstellar_envelope ALT "stellar envelope" D "circumstellar envelope" BT circumstellar_matter NT expanding_envelope RT Wolf-Rayet_star circumstellar_gas circumstellar_shell mass-loss ## circumstellar_gas circumstellar_gas D "circumstellar gas" BT circumstellar_matter RT circumstellar_disk circumstellar_dust circumstellar_envelope circumstellar_grain circumstellar_shell ## circumstellar_grain circumstellar_grain D "circumstellar grain" BT circumstellar_matter NT circumstellar_dust RT R_Coronae_Borealis_star circumstellar_gas ## circumstellar_matter circumstellar_matter ALT "circumstellar cloud" "stellar envelope" D "circumstellar matter" BT matter NT circumstellar_dust circumstellar_envelope circumstellar_gas circumstellar_grain RT circumstellar_disk bipolar_outflow circumplanetary_matter circumstellar_disk circumstellar_shell corona expanding_envelope gravitating_disk interplanetary_matter interstellar_matter mass-loss ## circumstellar_shell circumstellar_shell ALT "stellar envelope" D "circumstellar shell" BT shell NT dust_shell rotating_shell RT Be_star circumstellar_envelope circumstellar_gas circumstellar_matter extreme_carbon_star mass-loss shell_star stellar_wind ## civil_time civil_time D "civil time" BT time RT Universal_Time ephemeris_time mean_solar_time sidereal_time ## classical_nova classical_nova ALT "nova" D "classical nova" BT cataclysmic_variable_star nova HN "FVH: new (2007-NOV-15)" ## classical_T_Tauri_star classical_T_Tauri_star ALT "CTTS" D "classical T Tauri star" BT T_Tauri_star HN "FVH: new (2007-SEP-24)" ## classification classification D "classification" NT luminosity_classification spectral_classification RT morphology nomenclature taxonomy N "combine with other terms" ## clean_method clean_method D "clean method" RT data_processing image_processing image_reconstruction radio_astronomy ## clock clock D "clock" BT measuring_instrument timing_equipment NT atomic_clock chronometer RT time time_standard ## close_binary_star close_binary_star D "close binary star" BT binary_star NT Z_Andromedae_star beta_Lyrae_star cataclysmic_variable_star ellipsoidal_variable_star semi-detached_binary_star RT Roche_limit Roche_lobe X-ray_bright_point accretion_disk contact_binary_star synchronous_rotation tidal_friction ## closed_universe closed_universe D "closed universe" BT cosmology RT Big_Bang_theory open_universe steady-state_theory ## close_encounter close_encounter D "close encounter" RT stellar_dynamics ## cloud_monitor cloud_monitor D "cloud monitor" BT all-sky_camera RT Earth_atmosphere cloud HN "FVH: new (2007-SEP-21)" ## cloud cloud D "cloud" NT collapsing_cloud dust_cloud gas_cloud high-velocity_cloud noctilucent_cloud plasma_cloud RT Earth_atmosphere cloud_monitor N "combine with other terms" ## clumping clumping D "clumping" N "combine with other terms" ## clustering clustering D "clustering" RT galaxy_cluster star_cluster N "combine with other terms" ## cluster cluster D "cluster" NT galaxy_cluster protocluster star_cluster ## CNO_anomaly CNO_anomaly D "CNO anomaly" BT anomaly RT abundance abundance_ratio carbon_nitrogen_cycle metal_abundance ## CN_star CN_star D "cn star" BT giant RT carbon_star N "carbon-nitrogen star" ## coating coating D "coating" NT aluminum_coating antireflection_coating silver_coating RT lens mirror thin_film vapor_deposition N "combine with other terms" ## cobalt cobalt ALT "Co" D "cobalt (atomic number 27)" BT fundamental_chemical_element RT magnetic_star HN "FVH: new (2007-OCT-25)" ## cocoon_star cocoon_star D "cocoon star" BT infrared_source RT circumstellar_dust ## coelostat coelostat D "coelostat" BT reflecting_telescope NT heliostat RT drive siderostat telescope_mounting ## coherence coherence D "coherence" NT light_coherence RT laser maser N "combine with other terms" ## cold_Dark_Matter cold_Dark_Matter D "cold Dark Matter" BT Dark_Matter RT Dark_Energy baryonic_Dark_Matter cosmology CN "FVH: added RT DARK_ENERGY (2007-SEP-21)" ## collapse collapse D "collapse" NT gravitational_collapse N "combine with other terms" ## collapsed_star collapsed_star ALT "collapsed object" "collapsing star" D "collapsed star" BT star NT black_hole neutron_star pulsar stellar_black_hole RT degenerate_star stellar_evolution white_dwarf ## collapsing_cloud collapsing_cloud D "collapsing cloud" BT cloud NT protoplanetary_nebula RT protocluster protogalaxy protostar ## collimation collimation D "collimation" RT adjustment alignment_optics correction optics orientation ## collimator collimator D "collimator" RT beam_waveguide lens mirror optical_instrument ## collisional_excitation collisional_excitation D "collisional excitation" BT collision_process RT collision_broadening collision_spectroscopy collision_strength ionized_gas ion spectroscopy ## collisional_plasma collisional_plasma D "collisional plasma" BT plasma RT collision_process ion shock ## collision_broadening collision_broadening D "collision broadening" BT collision_process line_broadening RT collision_spectroscopy collision_strength collisional_excitation spectroscopic_analysis ## collision_process collision_process D "collision process" NT collision_broadening collisional_excitation RT collision_strength collisional_plasma ## collision collision D "collision" RT galaxy meteorite planet N "combine with other terms" ## collision_spectroscopy collision_spectroscopy D "collision spectroscopy" BT spectroscopy RT collision_broadening collision_strength collisional_excitation ## collision_strength collision_strength D "collision strength" RT collision_broadening collision_process collision_spectroscopy collisional_excitation ## color color D "color" BT optical_property RT color_equation color_excess color-luminosity_relation color-magnitude_relation color_photography color-redshift_relation colorimetry electromagnetic_radiation photometry spectrophotometry temperature visible_radiation ## color_equation color_equation D "color equation" RT color photometry ## color_excess color_excess D "color excess" RT color interstellar_reddening photometry ## colorimetry colorimetry D "colorimetry" RT color ## color_index color_index D "color index" RT intrinsic_color photometry two-color_diagram ## color-luminosity_relation color-luminosity_relation ALT "color luminosity relation" D "color-luminosity relation" RT Hertzsprung-Russell_diagram color photometry ## color-magnitude_relation color-magnitude_relation ALT "c m diagram" "c m relation" "c-m diagram" "c-m relation" "color magnitude relation" "color-magnitude diagram" D "color-magnitude relation" RT Hertzsprung-Russell_diagram color photometry ## color_photography color_photography D "color photography" BT photography RT color ## color-redshift_relation color-redshift_relation ALT "color redshift relation" D "color-redshift relation" RT color cosmology observational_cosmology ## color_vision color_vision D "color vision" BT vision RT dark_adaption ## comatic_aberration comatic_aberration D "comatic aberration (coma)" ALT "coma" BT optical_aberration RT astigmatism chromatic_aberration distortion field_curvature optical_system spherical_aberration CN "FVH: renamed after general conversion to singular (2007-11-27)" ## coma coma D "coma" RT comet galaxy ## cometary_globule cometary_globule D "cometary globule" BT dark_nebula globule interstellar_matter RT Bok_globule H_II_region protostar star_formation HN "FVH: new (2007-SEP-21)" ## comet comet D "comet" BT rotating_body NT Kreutz_sungrazer aperiodic_comet long_period_comet periodic_comet RT Oort_cloud Solar_System coma dirty_snowball_theory dust envelope halo interplanetary_matter jet meteor_stream meteorite meteoroid_dust_cloud meteoroid nucleus_celestial_object parabolic_orbit streamer tail N "named comet not included" ## compact_galaxy compact_galaxy D "compact galaxy" BT peculiar_galaxy NT N_galaxy RT BL_Lacertae_object active_galaxy quasar ## compact_H_II_region compact_H_II_region D "compact H II region" BT H_II_region ## compact_nebula compact_nebula D "compact nebula" BT nebula ## compact_nucleus compact_nucleus D "compact nucleus" BT galactic_nucleus nucleus_celestial_object NT Seyfert_nucleus RT Seyfert_galaxy active_galactic_nucleus compact_source ## compact_object compact_object D "compact object" NT BL_Lacertae_object black_hole compact_source neutron_star white_dwarf ## compact_source compact_source D "compact source" BT compact_object radio_source source RT compact_nucleus radio_structure ## companion_galaxy companion_galaxy D "companion galaxy" BT galaxy RT double_galaxy galaxy_group ## companion_star companion_star D "companion star" BT star NT primary_star secondary_star tertiary_star RT binary_star multiple_star ## comparison comparison D "comparison" N "combine with other terms" ## comparison_lamp comparison_lamp D "comparison lamp" BT lamp RT calibration spectrograph HN "FVH: new (2007-SEP-21)" ## comparison_star comparison_star D "comparison star" BT standard_star RT variable_star ## component component D "component" N "combine with other terms" ## composite_particle composite_particle D "composite particle" BT boson NT alpha_particle ion radical ## composition composition D "composition" RT planet N "combine with other terms" ## Compton_effect Compton_effect D "Compton effect" RT X-ray_scattering electron radiation_scattering ## Compton_scattering Compton_scattering D "Compton scattering" BT light_scattering radiation_scattering scattering NT Thomson_scattering RT Rayleigh_scattering electron inverse_Compton_scattering ## computer_application computer_application D "computer application" BT computing NT computer_simulation ## computer_model computer_model D "computer model" BT computing model RT computer_program computer_simulation mathematical_model numerical_simulation ## computer_program computer_program D "computer program" BT computing RT computer_model computer_simulation data_processing ## computer computer D "computer" NT array_processor microprocessor parallel_computer RT computing control_system data_center data_processing data_reduction data_storage peripheral ## computer_simulation computer_simulation D "computer simulation" BT computer_application simulation RT computer_model computer_program ## computing computing D "computing" NT computer_application computer_model computer_program data_processing data_retrieval data_storage database RT computer ## condensation condensation D "condensation" N "combine with other terms" ## conduction conduction D "conduction" RT energy-transfer thermal_conductivity N "combine with other terms" ## conjunction conjunction D "conjunction" RT opposition quadrature synodic_period syzygy N "refers to planet position" ## constant constant D "constant" NT astronomical_constant cosmological_parameter physical_constant CN "FVH: more physical hierarchy (2007-OCT-11)" ## constellation constellation D "constellation" RT astrology zodiac N "see appendix" ## contact_binary_star contact_binary_star D "contact binary star" BT binary_star NT beta_Lyrae_star ellipsoidal_variable_star RT close_binary_star eclipsing_binary_star equipotential_surface mass_exchange ## continental_drift continental_drift D "continental drift" RT continent geomagnetism geophysics paleomagnetism ## continent continent D "continent" RT Earth continental_drift ## contiuum contiuum D "contiuum" RT continuum_radiation spectrum N "combine with other terms" ## continuous_spectrum continuous_spectrum D "continuous spectrum" BT spectrum RT light_emission spectroscopic_analysis spectroscopy visible_spectrum ## continuum_radiation continuum_radiation D "continuum radiation" BT electromagnetic_radiation radiation NT X-ray_continuum ultraviolet_continuum RT contiuum photosphere ## contour_map contour_map D "contour map" BT map RT isophot radio_structure ## contraction contraction D "contraction" N "combine with other terms" ## contrast contrast D "contrast" N "combine with other terms" ## control_system control_system D "control system" NT autoguider remote_control_system RT computer drive guide_system microprocessor pointing_accuracy pointing_error quadrant_detector telescope_instrument telescope tracking ## convection convection D "convection" RT Hayashi_track Rayleigh_number convective_envelope convective_shell convective_zone dredge_up energy-transfer envelope granulation line_broadening mass-transfer thermal_instability thermal_structure turbulence_Earth_atmosphere turbulence_star_atmosphere ## convective_envelope convective_envelope D "convective envelope" RT convection ## convective_shell convective_shell D "convective shell" BT shell RT convection ## convective_zone convective_zone D "convective zone" RT convection ## cooling cooling D "cooling" N "combine with other terms" ## cooling_flow cooling_flow D "cooling flow" RT accretion_disk galaxy star_formation ## coordinated_Universal_Time coordinated_Universal_Time ALT "UTC" D "coordinated Universal Time" BT Universal_Time RT UT1 HN "FVH: new (2007-OCT-3)" ## coordinate_system coordinate_system D "coordinate system" NT celestial_coordinate_system horizon_coordinate_system inertial_coordinate_system RT aberration astrometry heliocentric_correction position reference_frame reference_system spherical_coordinate true_position N "coordinate not included" "planet and satellite surface" ## copper copper ALT "Cu" D "copper (atomic number 29)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## core core D "core" RT Earth planet stellar_interior N "combine with other terms" ## corona corona ALT "coronas" D "corona" NT E_corona F_corona K_corona coronal_hole coronal_line coronal_loop coronal_plume solar_corona RT circumstellar_matter halo ionization mass-loss stellar_atmosphere ## coronagraph coronagraph D "coronagraph" BT instrument optical_instrument RT camera solar_corona solar_observatory spectroheliograph ## coronal_dimming coronal_dimming D "solar coronal dimming" RT solar_corona HN "FVH: new (2007-OCT-29)" ## coronal_hole coronal_hole D "coronal hole" BT corona RT solar_corona solar_wind ## coronal_line coronal_line D "coronal line" BT corona emission_line RT solar_corona ## coronal_loop coronal_loop D "coronal loop" BT corona RT chromosphere solar_activity solar_corona ## coronal_mass_ejection coronal_mass_ejection ALT "CME" D "coronal mass ejection" BT mass-loss RT corpuscular_emission solar_corona ## coronal_plume coronal_plume D "coronal plume" BT corona RT solar_corona ## coronal_transient coronal_transient D "coronal transient" RT solar_corona ## coronal_wave coronal_wave D "solar coronal wave" BT Alfven_wave RT solar_corona HN "FVH: new (2007-OCT-29)" ## corpuscular_emission corpuscular_emission D "corpuscular emission" RT coronal_mass_ejection ## correction correction D "correction" RT adjustment alignment_optics collimation error selection_effect N "combine with other terms" ## corrector_plate corrector_plate D "corrector plate" BT lens optical_component RT Schmidt_camera Schmidt_telescope catadioptric_system field_corrector ## correlation correlation D "correlation" NT auto-correlation cross-correlation interferometric_correlation luminosity-dispersion_relation RT interferometry receiver HN "FVH: new (2007-NOV-1)" ## cosmic_abundance cosmic_abundance D "cosmic abundance" BT abundance RT cosmology ## cosmic_background_radiation cosmic_background_radiation D "cosmic background radiation" BT background_radiation ## cosmic cosmic D "cosmic" N "combine with other terms" ## cosmic_electrodynamics cosmic_electrodynamics D "cosmic electrodynamics" BT electrodynamics electromagnetic_theory RT magnetohydrodynamics ## cosmic_noise cosmic_noise D "cosmic noise" BT noise radio_interference NT microwave_background RT background_noise background_radiation microwave_emission radio_background ## cosmic_ray_astronomy cosmic_ray_astronomy D "cosmic ray astronomy" BT astronomy RT balloon-borne_instrument high-energy_astrophysics rocket-borne_instrument satellite-borne_instrument ## cosmic_ray cosmic_ray ALT "cosmic radiation" "primary cosmic ray" D "cosmic ray" BT background_radiation high-energy_radiation radiation NT Galactic_cosmic_ray RT Cerenkov_counter Cerenkov_radiation cosmic_ray_shower cosmic_ray_source forbush_effect inverse_Compton_effect secondary_cosmic_ray ## cosmic_ray_shower cosmic_ray_shower ALT "air shower" "auger shower" D "cosmic ray shower" RT cosmic_ray phosphorescent_scintillation secondary_cosmic_ray ## cosmic_ray_source cosmic_ray_source D "cosmic ray source" BT source RT cosmic_ray ## cosmic_string cosmic_string ALT "string" D "cosmic string" RT cosmology intergalactic_matter interstellar_matter large_scale_structure ## cosmic_year cosmic_year D "cosmic year" BT year RT Galactic_rotation ## cosmochemistry cosmochemistry ALT "astrochemistry" "cosmic chemistry" D "cosmochemistry" BT chemistry RT astrobiology cosmology interstellar_molecule molecular_astrophysics ## cosmochronology cosmochronology ALT "nucleocosmochronology" D "cosmochronology" RT age cosmology nuclear_fission HN "ES: new (2007-OCT-8)" ## cosmogony cosmogony D "cosmogony" BT astronomy NT relativity RT cosmology protocluster protogalaxy protoplanetary_nebula universe ## cosmological_constant cosmological_constant ALT "Lambda" D "cosmological constant" BT cosmological_parameter RT Dark_Energy Omega_Lambda cosmology CN "FVH: added ALT lambda (2007-SEP-21)" ## cosmological_distance_scale cosmological_distance_scale D "cosmological distance scale" BT distance_scale RT Hubble_constant cosmological_parameter deceleration_parameter observational_cosmology redshift redshift_distance_relation redshift_magnitude_relation ## cosmological_model cosmological_model D "cosmological model" N "see under cosmology" ## cosmological_parameter cosmological_parameter D "cosmological parameter/constant" BT constant NT Hubble_constant Omega_parameter cosmological_constant deceleration_parameter sigma8 RT cosmological_distance_scale cosmology HN "FVH: new (2007-SEP-21)" CN "FVH: renamed *_parameter, since some of them aren't necessarily constant (2007-OCT-26)" ## cosmology cosmology D "cosmology" BT astronomy NT Bianchi_cosmology Big_Bang_theory Einstein_universe Friedmann_universe Goedel_universe Lemaitre_universe closed_universe de_Sitter_universe dirac_cosmology expanding_universe hierarchical_cosmology inflationary_universe open_universe oscillating_universe primordial_fireball quantum_cosmology relativistic_cosmology steady-state_theory RT Dark_Energy Dark_Matter Hubble_constant Hubble_diagram Hubble_law Hubble_radius Hubble_time Omega_parameter Tully-Fisher_relation Type_Ia_supernova anthropic_principle astrophysics cold_Dark_Matter color-redshift_relation cosmic_abundance cosmic_string cosmochemistry cosmochronology cosmogony cosmological_constant cosmological_parameter early_universe galaxy_count galaxy_distribution galaxy_evolution general_theory_of_relativity large_scale_structure microwave_background missing_mass protocluster protogalaxy redshift redshift_distance_relation redshift_magnitude_relation relativistic_astrophysics relativistic_velocity space-time_curvature stellar_evolution universe white_hole CN "FVH: added RT DARK_ENERGY, RT LARGE_SCALE_STRUCTURE (2007-SEP-21)" ## Coude_focus Coude_focus D "Coude focus" BT focus RT Cassegrain_focus Nasmyth_focus Newtonian_focus prime_focus ## Coude_spectrum Coude_spectrum D "Coude spectrum" BT high-resolution_spectrum RT echelle_spectrograph ## Coude_spectrograph Coude_spectrograph D "Coude spectrograph" BT spectrograph RT high-resolution_spectrum high-resolution_spectrosopy ## counter counter ALT "count" D "counter" BT measuring_instrument NT scintillation_counter RT counting data_acquisition photon_counting_system ## counting counting ALT "count" D "counting" RT counter data_acquisition ## coupling coupling D "coupling" N "combine with other terms" ## crater crater D "crater" NT impact_crater RT Earth Moon basin ejecta meteor planet volcano N "combine with other terms" ## cross-correlation cross-correlation ALT "cross correlation" D "cross-correlation" BT correlation RT auto-correlation data_processing interferometric_correlation ## crustal_dynamics crustal_dynamics D "crustal dynamics" RT Moon crust mantle ## crust crust D "crust" RT Earth Moon crustal_dynamics mantle planet N "combine with other terms" ## cryogenics cryogenics D "cryogenics" RT cryostat outgassing temperature_control ## cryostat cryostat D "cryostat" RT cryogenics temperature_control ## CS CS D "CS molecule" BT carbon_compound hydrocarbon interstellar_molecule HN "FVH: new (2007-OCT-2)" ## curium curium ALT "Cm" D "curium (atomic number 96)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## current current D "current" RT antenna current_sheet electric_current N "combine with other terms" ## current_sheet current_sheet D "current sheet" RT antenna current electric_current ## curve_of_growth curve_of_growth D "curve of growth" RT abundance chemical_element ## cusp_crossing cusp_crossing D "cusp crossing" RT caustic_crossing caustic cusp gravitational_lensing HN "FVH: new (2007-OCT-8)" ## cusp cusp D "cusp" RT caustic_crossing cusp_crossing gravitational_lensing HN "FVH: new (2007-OCT-8)" ## cyanoacetylene cyanoacetylene D "cyanoacetylene" BT carbon_compound ## cyanodiacetylene cyanodiacetylene D "cyanodiacetylene" BT carbon_compound ## cyanogen cyanogen ALT "CN" D "cyanogen" BT carbon_compound ## cyanogen_line cyanogen_line D "cyanogen line" BT spectral_line RT absorption_line ## cyanopolyene cyanopolyene D "cyanopolyene" BT carbon_compound CN "FVH: corrected spelling (2007-OCT-2)" ## cycle cycle D "cycle" RT period ## cyclotron_radiation cyclotron_radiation D "cyclotron radiation" BT electromagnetic_radiation radiation synchrotron_radiation RT radiation_mechanism ## damping_constant damping_constant D "damping constant" RT line_formation radiation_damping radiative_braking ## Danjon_astrolabe Danjon_astrolabe D "Danjon astrolabe" BT astrolabe ## dark_adaption dark_adaption ALT "retinal adaption" D "dark adaption" RT color_vision darkness night_vision vision ## dark_cloud dark_cloud D "dark cloud" BT interstellar_matter RT C_II_region ## dark-current_calibration dark-current_calibration D "dark-current calibration" BT calibration RT CCD_detector HN "FVH: new (2007-OCT-3)" ## Dark_Energy Dark_Energy ALT "dark energy" D "Dark Energy" RT Dark_Matter Hubble_law cold_Dark_Matter cosmological_constant cosmology early_universe galaxy_count galaxy_distribution general_theory_of_relativity redshift_distance_relation redshift_magnitude_relation space-time_curvature universe HN "FVH: new (2007-SEP-21)" ## Dark_Matter Dark_Matter D "Dark Matter" BT intergalactic_matter interstellar_matter NT baryonic_Dark_Matter cold_Dark_Matter RT Dark_Energy Galactic_rotation cosmology elementary_particle galaxy_rotation_curve mass_distribution ## dark_nebula dark_nebula ALT "absorption nebula" D "dark nebula" BT interstellar_matter nebula NT Bok_globule cometary_globule RT Wolf_diagram globule star_formation ## darkness darkness D "darkness" RT dark_adaption diurnal_variation electromagnetic_radiation optical_property visible_radiation ## darkroom darkroom D "darkroom" RT photographic_processing photography ## darmtadtium darmtadtium ALT "Ds" D "darmtadtium (atomic number 110)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## DA_star DA_star D "DA white dwarf star" BT white_dwarf RT DB_star DO_star CN "FVH: modified from original DA_star (2007-OCT-1)" ## data_acquisition data_acquisition D "data acquisition" RT counter counting data_analysis digital_recorder observation observing_technique ## data_analysis data_analysis D "data analysis" BT analysis NT error_analysis RT data_acquisition data_processing data_reduction data_storage determination ## database database ALT "data base" D "database" BT computing RT data_center data_retrieval data_storage virtual_observatory ## data_center data_center D "data center" RT computer data_processing data_reduction data_retrieval data_storage database on-line_system virtual_observatory ## data_processing data_processing D "data processing" BT computing NT Monte_Carlo_technique data_reduction numerical_analysis RT auto-correlation clean_method computer_program computer cross-correlation data_analysis data_center data_retrieval data_storage error_analysis observing_technique on-line_system reduction_method ## data_reduction data_reduction D "data reduction" BT data_processing RT computer data_analysis data_center data_retrieval data_storage error_analysis fine_analysis reduction_method ## data_retrieval data_retrieval D "data retrieval" BT computing RT data_center data_processing data_reduction data_storage database virtual_observatory ## data_storage data_storage D "data storage" BT computing NT RAID_array analog_recorder RT computer data_analysis data_center data_processing data_reduction data_retrieval database ## DB_star DB_star D "DB white dwarf star" BT helium-rich_star white_dwarf RT DA_star DO_star HN "FVH: new (2007-OCT-1)" ## DDO_photometry DDO_photometry D "DDO photometry" BT medium_band_photometry photometric_system ## dead-time_calibration dead-time_calibration D "dead-time calibration" BT calibration HN "FVH: new (2007-OCT-3)" ## decay_oscillation decay_oscillation D "decay of oscillation" RT amplitude oscillation radiation_damping ## deceleration deceleration D "deceleration" RT acceleration deceleration_parameter ## deceleration_parameter deceleration_parameter ALT "q-parameter" D "deceleration parameter" BT cosmological_parameter RT cosmological_distance_scale deceleration ## Declination Declination ALT "celestial latitude" D "Declination" BT latitude equatorial_coordinate_system RT Right_Ascension celestial_equator equator equatorial_zone ## deconvolution deconvolution D "deconvolution" N "combine with other terms" ## defect defect D "defect" N "combine with other terms" ## deformation deformation D "deformation" N "combine with other terms" ## degenerate_dwarf degenerate_dwarf D "degenerate dwarf star" BT degenerate_star NT white_dwarf ## degenerate_matter degenerate_matter D "degenerate matter" BT matter NT black_hole degenerate_star ## degenerate_star degenerate_star D "degenerate star" BT degenerate_matter subluminous_star NT degenerate_dwarf neutron_star pulsar RT collapsed_star mass-radius_relation ## delta_delphini_star delta_delphini_star D "delta Delphini star" BT delta_Scuti_star pulsating_variable_star ## delta_Scuti_star delta_Scuti_star ALT "AI Velorum star" D "delta Scuti star" BT multi-periodic_variable_star pulsating_variable_star short_period_variable_star NT delta_delphini_star RT He_II_ionization_zone dwarf_Cepheid kappa_mechanism non-radial_pulsation radial_pulsation ## dense_cloud dense_cloud D "dense cloud" BT interstellar_matter nebula ## densitometer densitometer D "densitometer" BT measuring_instrument RT densitometry microdensitometer ## densitometry densitometry D "densitometry" RT densitometer ## density_bounded density_bounded D "density bounded" RT density ## density density ALT "specific gravity" D "density" NT atmospheric_density electron_density energy_density gas_density mass_density RT Rankine-Hugoniot_relation density_bounded density_distribution density_fluctuation density_perturbation density_variation density_wave_model ## density_distribution density_distribution D "density distribution" RT density ## density_fluctuation density_fluctuation D "density fluctuation" RT density ## density_perturbation density_perturbation D "density perturbation" RT density ## density_variation density_variation D "density variation" RT density ## density_wave_model density_wave_model D "density wave model" RT density ## descending_node descending_node D "descending node" BT node CN "FVH: moved NODES to BT (2007-OCT-1)" ## design design D "design" NT engineering RT research N "combine with other terms" ## de_Sitter_universe de_Sitter_universe D "de Sitter universe" BT cosmology ## destruction destruction D "destruction" N "combine with other terms" ## detached_binary_star detached_binary_star D "detached binary star" BT binary_star NT W_Ursae_Majoris_star RT semi-detached_binary_star ## detection detection D "detection" NT signal_detection N "combine with other terms" ## detector_array detector_array D "detector array" BT array RT array_processor ## detector detector D "detector" BT instrument NT X-ray_detector dust_detector infrared_detector multi-channel_detector photographic_emulsion photomultiplier_tube radiometer superconducting_tunnel_junction synchronous_detector two-dimensional_detector ultraviolet_detector RT charge-coupled_device charge-injection_device charge-transfer_device limiting_magnitude pixel quantum_efficiency receiver remote_sensing semiconductor_device sensitivity shot_noise shutter signal_detection telescope_instrument CN "FVH: added NT SUPERCONDUCTING_TUNNEL_JUNCTION (2007-SEP-21)" N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## determination determination D "determination" RT data_analysis measurement quantization ## deuterium deuterium D "deuterium, an isotope of hydrogen" BT hydrogen RT isotope ## D_galaxy D_galaxy D "rotationally symmetric elliptical galaxy (Yerkes classification scheme)" BT elliptical_galaxy galaxy NT cD_galaxy RT Yerkes_classification massive_galaxy ## diagram diagram D "diagram" N "combine with other terms" ## diameter diameter D "diameter" BT dimension NT angular_diameter isophotal_diameter RT Baade-Wesselink_method occultation surface_gravity N "combine with other terms" ## diamond_ring_effect diamond_ring_effect D "diamond ring effect" RT Sun bailys_bead solar_eclipse ## dichroic_mirror dichroic_mirror D "dichroic mirror" BT mirror RT optical_film optical_filter ## Dicke_radiometer Dicke_radiometer D "Dicke radiometer" BT radiometer ## differential_equation differential_equation D "differential equation" BT mathematical_analysis ## differential_image_motion_monitor differential_image_motion_monitor ALT "DIMM" D "differential image-motion monitor" BT seeing_monitor HN "FVH: new (2007-SEP-21)" ## differential_rotation differential_rotation D "differential rotation" BT rotation RT Galactic_rotation galaxy galaxy_rotation_curve globular_star_cluster tidal_disruption tidal_distortion CN "FVH: added RT Galactic_rotation, RT galaxy_rotation_curve (2007-OCT-5)" ## diffraction diffraction D "diffraction" NT X-ray_diffraction RT Airy_disk Rayleigh_criterion diffraction_patterns interference_wave shadow_band ## diffraction_grating diffraction_grating ALT "grating" D "diffraction grating" BT optical_component NT VPH_grating echelle_grating objective_grating reflection_grating transmission_grating RT grating_spectrograph grism spectrum spectrograph ## diffraction_patterns diffraction_patterns D "diffraction patterns" RT diffraction ## diffuse_nebula diffuse_nebula D "diffuse nebula" BT nebula ## diffuse_radiation diffuse_radiation D "diffuse radiation" N "combine with other terms" ## diffusion diffusion D "diffusion" N "combine with other terms" ## digital_image digital_image D "digital image" BT image ## digital_recorder digital_recorder D "digital recorder" RT data_acquisition ## dimension dimension D "dimension" NT diameter N "combine with other terms" ## diode_array diode_array D "diode array" BT array multi-channel_detector RT reticon_array ## diode diode D "diode" BT electronic_equipment ## dioptric_system dioptric_system D "dioptric system" BT optical_system RT lens optical_telescope ## dipole_antenna dipole_antenna ALT "dipole antennas" D "dipole antenna" BT antenna directional_antenna RT dipole ## dipole dipole D "dipole" NT half-wave_dipole RT dipole_antenna electric_charge electric_dipole ## dirac_cosmology dirac_cosmology D "Dirac cosmology" BT cosmology ## directional_antenna directional_antenna ALT "directional antennas" D "directional antenna" BT antenna NT Mills_cross_antenna Yagi_antenna dipole_antenna parabolic_antenna ## dirty_snowball_theory dirty_snowball_theory D "dirty snowball theory" RT comet nucleus_celestial_object ## discoloration discoloration D "discoloration" N "combine with other terms" ## discoveries discoveries D "discoveries" RT research space_exploration N "combine with other terms" ## discrete_radio_source discrete_radio_source D "discrete radio source" BT radio_source ## dish_antenna dish_antenna ALT "dish antennas" D "dish antenna" BT radio_telescope RT antenna parabolic_reflector radar_telescope ## disintegration disintegration D "disintegration" N "combine with other terms" ## disk_flaring disk_flaring D "disc flaring" UK "disk flaring" RT disk morphology ## disk_galaxy disk_galaxy D "disc galaxy" UK "disk galaxy" BT galaxy NT lenticular_galaxy spiral_galaxy RT disk mass_distribution ## disk_population disk_population D "disc population" UK "disk population" BT population_II_star RT Galactic_plane disk stellar_population ## disk disk D "discs" UK "disk" NT accretion_disk circumstellar_disk gaseous_disk gravitating_disk RT disk_flaring disk_galaxy disk_population disk_star ## disk_star disk_star D "disc star" UK "disk star" BT population_II_star RT Galactic_plane disk gaseous_disk ## dispersion dispersion D "dispersion" N "combine with other terms" ## disruption disruption D "disruption" N "combine with other terms" ## dissipation dissipation D "dissipation" N "combine with other terms" ## distance distance D "distance" RT Bodes_law absolute_magnitude distance_indicator distance_measurement distance_modulus distance_scale light_year parallax parsec range_finder trigonometric_parallax ## distance_indicator distance_indicator D "distance indicator" RT distance distance_measurement distance_modulus distance_scale ## distance_measurement distance_measurement D "distance measurement" NT Cepheid_distance Faber-Jackson_distance RGB_tip_distance SBF_distance RT distance distance_indicator distance_scale ## distance_modulus distance_modulus ALT "modulus" D "distance modulus" RT absolute_magnitude distance distance_indicator distance_scale parallax ## distance_scale distance_scale D "distance scale" NT cosmological_distance_scale RT Astronomical_Unit distance distance_indicator distance_measurement distance_modulus parsec ## distortion distortion D "distortion" BT optical_aberration RT astigmatism chromatic_aberration comatic_aberration field_curvature optical_system spherical_aberration ## distribution_function distribution_function D "distribution function" BT function RT distribution_in_space frequency_distribution statistics N "in mathematics" ## distribution_in_space distribution_in_space D "distribution in space" RT distribution_function N "combine with other terms" ## diurnal_parallax diurnal_parallax D "diurnal parallax" BT parallax NT horizontal_parallax RT zenith_distance ## diurnal_phenomena diurnal_phenomena D "diurnal phenomena" RT diurnal_variation ## diurnal_variation diurnal_variation D "diurnal variation" RT darkness diurnal_phenomena ## D_layer D_layer ALT "D region" D "D layer" RT Earth_atmosphere ionosphere ## D_line D_line D "D line" BT spectral_line RT absorption_spectrum ## dome dome ALT "telescope dome" D "dome" RT dome_seeing observatory telescope temperature_control ventilation N "excluding lunar dome" ## dome_seeing dome_seeing D "dome seeing" BT seeing RT dome ventilation ## Doppler_broadening Doppler_broadening D "Doppler broadening" BT line_broadening RT Doppler_effect Stark_broadening Zeeman_splitting line_width natural_line_width pressure_broadening ## Doppler_effect Doppler_effect D "Doppler effect" NT blueshift redshift RT Doppler_broadening line_shift radar radial_velocity spectroscopic_analysis spectroscopic_binary_star stellar_motion ## DO_star DO_star D "DO white dwarf star" BT white_dwarf NT PG1159_star RT DA_star DB_star HN "FVH: new (2007-OCT-9)" ## double_galaxy double_galaxy ALT "binary galaxy" D "double galaxy" BT binary_system galaxy RT companion_galaxy galaxy_merger ## double-mode_Cepheid double-mode_Cepheid ALT "beat_Cepheid" "double mode Cepheid" D "double-mode Cepheid" BT Cepheid double-mode_variable_star pulsating_variable_star RT double-mode_pulsation ## double-mode_pulsation double-mode_pulsation ALT "double mode pulsation" D "double-mode pulsation" BT multi-periodic_pulsation RT double-mode_Cepheid double-mode_variable_star pulsating_variable_star ## double-mode_variable_star double-mode_variable_star ALT "double mode variable star" D "double-mode variable star" BT multi-periodic_variable_star pulsating_variable_star NT RR_Lyrae_star double-mode_Cepheid RT double-mode_pulsation ## double_quasar double_quasar D "double quasar" BT gravitationally_lensed_source RT gravitational_deflection gravitational_lensing quasar ## DQ_Herculis_star DQ_Herculis_star D "DQ Herculis star" BT eclipsing_binary_star slow_nova ## dredge_up dredge_up D "dredge up" RT convection giant metal_abundance stellar_atmosphere stellar_interior ## drift_scan drift_scan D "drift scan" RT photometry radio_structure surface_photometry ## drift_wave drift_wave D "drift wave" BT wave ## drive drive D "drive" RT coelostat control_system siderostat telescope ## dubnium dubnium ALT "Db" D "dubnium (atomic number 105)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## dust_cloud dust_cloud D "dust cloud" BT cloud interstellar_matter RT dust interstellar_dust ## dust_detector dust_detector D "dust detector" BT detector RT dust ## dust dust ALT "cosmic dust" D "dust" BT intergalactic_matter interstellar_matter NT interplanetary_dust interstellar_dust zodiacal_dust RT comet dust_cloud dust_detector dust_grain dust_nebula dust_shell dust_storm gas_to_dust_ratio ## dust_grain dust_grain D "dust grain" BT interstellar_matter RT adsorption dust ## dust_nebula dust_nebula D "dust nebula" BT interstellar_matter nebula RT dust ## dust_shell dust_shell D "dust shell" BT circumstellar_shell shell RT circumstellar_dust dust symbiotic_star ## dust_storm dust_storm D "dust storm" RT dust planet surface_of_celestial_body ## dwarf_Cepheid dwarf_Cepheid D "dwarf Cepheid" BT irregular_variable_star multi-periodic_variable_star pulsating_variable_star RT Cepheid delta_Scuti_star ## dwarf_galaxy dwarf_galaxy D "dwarf galaxy" BT galaxy peculiar_galaxy ## dwarf_nova dwarf_nova ALT "DN" D "dwarf nova" BT cataclysmic_variable_star eruptive_binary_star NT SU_Ursae_Majoris_star SX_Arietis_star U_Geminorum_star WZ_Sagittae_star Z_Camelopardalis_star RT AM_Canum_Venaticorum_star UV_Persei_star UX_Ursae_Majoris_star X-ray_binary_star accretion_disk emission_line_star CN "FVH: total update (2007-SEP-24)" ## dwarf_planet dwarf_planet D "dwarf planet" BT rotating_body NT Ceres Pluto RT planet ## dwarf dwarf D "dwarf star" BT main_sequence_star NT A_dwarf B_dwarf F_dwarf G_dwarf K_dwarf M_dwarf O_dwarf black_dwarf flare_star late-type_dwarf nearby_dwarf RT brown_dwarf low-luminosity_star low-mass_star luminosity_classification main_sequence subdwarf N "the term alone refers to main sequence star, but subterms may refer to evolved star" ## dynamical_evolution dynamical_evolution D "dynamical evolution" BT evolution ## dynamical_friction dynamical_friction D "dynamical friction" BT friction RT radiative_braking ## dynamical_parallax dynamical_parallax D "dynamical parallax" BT parallax RT binary_star kinematic_parallax moving_cluster_parallax ## dynamical_time dynamical_time D "dynamical time" BT time ## dynamics dynamics D "dynamics" N "combine with other terms" ## dynamo_theory dynamo_theory D "dynamo theory" RT magnetic_field ## dysprosium dysprosium ALT "Dy" D "dysprosium (atomic number 66)" BT fundamental_chemical_element rare_earth HN "FVH: new (2007-OCT-25)" ## early-type_emission_star early-type_emission_star ALT "early type emission star" D "early-type emission star" BT emission_line_star NT Ae_star Be_star Oe_star Oef_star Of_star Wolf-Rayet_star ## early-type_galaxy early-type_galaxy ALT "early type galaxy" D "early-type galaxy" BT galaxy ## early-type_star early-type_star ALT "blue star" "early type star" "hot star" D "early-type star" BT ultraviolet_source NT A_star B_star O_star OB_star early-type_variable_star faint_blue_star RT orion_population_star N "see also gas" ## early-type_supergiant early-type_supergiant ALT "early type supergiant star" D "early-type supergiant star" BT supergiant NT A_supergiant B_supergiant O_supergiant OB_supergiant RT luminous_blue_variable_star ## early-type_variable_star early-type_variable_star ALT "early type variable star" D "early-type variable star" BT early-type_star NT S_Doradus_star SX_Arietis_star beta_Cephei_star luminous_blue_variable_star RT A_star B_star O_star ## early_universe early_universe D "early universe" RT Big_Bang_theory Dark_Energy cosmology ## Earth Earth D "Earth" BT planet RT Earth_sciences Solar_System continent core crater crust earthquake geocorona geodesy geoid geomagnetism geophysics glaciology mantle perigee polar_cap radiation_belt scintillation seismology sidereal_time solar-terrestrial_relation space_geodesy topography troposphere N "combine with other terms" ## Earth_atmosphere Earth_atmosphere ALT "terrestrial atmosphere" D "Earth atmosphere" BT atmosphere RT D_layer E_layer F_layer aeronomy atmospheric_extinction atmospheric_scattering atmospheric_scintillation atmospheric_window cloud_monitor cloud exosphere ionosphere magnetosphere mesopause mesosphere meteorology noctilucent_cloud ozone_layer scale_height scintillation seeing stratopause stratosphere telluric_line thermosphere tropopause troposphere turbulence_Earth_atmosphere twilight upper_atmosphere ## Earth-Moon_system Earth-Moon_system ALT "Earth Moon system" D "Earth-Moon system" RT Solar_System annual_equation equation_of_the_center lunar_theory tidal_friction two-body_problem ## Earth_orbit Earth_orbit D "Earth orbit" RT annual_equation aphelion ecliptic ecliptic_coordinate_system ecliptic_plane equation_of_time perihelion solar_parallax time tropical_year zodiac ## earthquake earthquake D "earthquake" RT Earth moonquake ## Earth_rotation Earth_rotation D "Earth rotation" BT rotation RT Chandler_wobble astrometry equation_of_the_equinox nutation polar_motion precession time ## Earth_sciences Earth_sciences D "Earth sciences" BT scientific_field NT geodesy geology geophysics glaciology RT Earth geophysical_observatory ## Earthshine Earthshine D "Earthshine" RT Moon ## eccentric_anomaly eccentric_anomaly D "eccentric anomaly" BT orbital_anomaly ## eccentricity eccentricity D "eccentricity" BT orbital_element RT elliptical_orbit ## echelle_grating echelle_grating ALT "echelons" D "echelle grating" BT diffraction_grating RT echelle_spectrum objective_grating reflection_grating spectrograph transmission_grating ## echelle_spectrum echelle_spectrum D "echelle spectrum" BT high-resolution_spectrum spectrum RT echelle_grating echelle_spectrograph ## echelle_spectrograph echelle_spectrograph ALT "echelle spectrometer" D "echelle spectrograph" BT spectrograph RT Coude_spectrum echelle_spectrum high-resolution_spectrum high-resolution_spectrosopy ## eclipse eclipse D "eclipse" NT annular_eclipse lunar_eclipse partial_eclipse solar_eclipse total_eclipse RT eclipsing_binary_star occultation penumbra transit umbra ## eclipsing_binary_star eclipsing_binary_star ALT "eclipsing star" "eclipsing variable star" "photometric binary star" D "eclipsing binary star" BT binary_star variable_star NT Algol_variable_star DQ_Herculis_star R_Canis_Majoris_star W_Ursae_Majoris_star beta_Lyrae_star upsilon_Sagittarii_star RT Roche_lobe contact_binary_star eclipse ellipsoidal_variable_star interacting_binary_star partial_eclipse photometric_element spectroscopic_binary_star total_eclipse ## ecliptic_coordinate_system ecliptic_coordinate_system D "ecliptic coordinate system" BT celestial_coordinate_system RT Earth_orbit ecliptic ecliptic_latitude ecliptic_longitude ecliptic_pole ## ecliptic ecliptic D "ecliptic" RT Earth_orbit ecliptic_coordinate_system ecliptic_plane ecliptic_pole equinox obliquity_of_ecliptic solstice zodiac ## ecliptic_latitude ecliptic_latitude D "ecliptic latitude" BT latitude RT ecliptic_coordinate_system ecliptic_longitude ecliptic_pole ## ecliptic_longitude ecliptic_longitude D "ecliptic longitude" BT longitude RT ecliptic_coordinate_system ecliptic_latitude ecliptic_pole ## ecliptic_plane ecliptic_plane D "ecliptic plane" RT Earth_orbit ecliptic ecliptic_pole obliquity_of_ecliptic ## ecliptic_pole ecliptic_pole D "ecliptic pole" BT pole NT North_Ecliptic_Pole South_Ecliptic_Pole RT ecliptic ecliptic_coordinate_system ecliptic_latitude ecliptic_longitude ecliptic_plane ## E_corona E_corona ALT "E component" "E-corona" D "E corona" BT corona ## Eddington_limit Eddington_limit D "Eddington limit" RT gravitational_force radiation_pressure stellar_interior ## edge_effect edge_effect D "edge effect" RT galaxy photography ## Edgeworth-Kuiper_belt Edgeworth-Kuiper_belt ALT "Kuiper belt" D "Edgeworth-Kuiper belt" RT Edgeworth-Kuiper_belt_object Solar_System asteroid trans-Neptunian_object HN "FVH: new (2007-OCT-2)" ## Edgeworth-Kuiper_belt_object Edgeworth-Kuiper_belt_object ALT "EKO" "KBO" "Kuiper belt object" D "Edgeworth-Kuiper belt object" BT trans-Neptunian_object RT Edgeworth-Kuiper_belt ## effective_temperature effective_temperature D "effective temperature" BT temperature RT electromagnetic_radiation photometry radiation standard_candle ## e-folding_time e-folding_time D "e-folding time" RT oscillation ## E_galaxy E_galaxy D "elliptical galaxy (Yerkes classification scheme)" BT elliptical_galaxy NT Ep_galaxy RT Yerkes_classification HN "FVH: new (2007-OCT-12)" ## Einstein_coefficient Einstein_coefficient D "Einstein coefficient" RT absorption_coefficient emission_coefficient ## Einstein_effect Einstein_effect ALT "Einstein shift" D "Einstein effect" RT gravitational_redshift ## einsteinium einsteinium ALT "Es" D "einsteinium (atomic number 99)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Einstein_ring Einstein_ring D "Einstein ring" BT gravitationally_lensed_source RT gravitational_deflection gravitational_lensing ## Einstein_universe Einstein_universe D "Einstein universe" BT cosmology ## ejecta ejecta D "ejecta" RT Wolf-Rayet_star crater ## ejection ejection D "ejection" N "combine with other terms" ## elasticity elasticity D "elasticity" N "combine with other terms" ## E_layer E_layer ALT "E region" D "E layer" RT Earth_atmosphere ionosphere N "refers to Earth atmosphere" ## electrical_property electrical_property D "electrical property" RT electricity ## electric_charge electric_charge D "electric charge" RT dipole electricity electrostatic_wave ## electric_current electric_current D "electric current" RT current_sheet current electricity ## electric_dipole electric_dipole D "electric dipole" RT dipole electricity ## electric_field electric_field D "electric field" RT Paul_trap electricity electrostatic_wave force ## electricity electricity D "electricity" RT electric_charge electric_current electric_dipole electric_field electrical_property ## electrode electrode D "electrode" NT cathode photocathode RT image_tube photomultiplier_tube ## electrodynamics electrodynamics D "electrodynamics" NT cosmic_electrodynamics ## electromagnetic electromagnetic D "electromagnetic" N "combine with other terms" ## electromagnetic_field electromagnetic_field D "electromagnetic field" RT electromagnetic_forces field_equation quantum_field_theory radiation_field ## electromagnetic_forces electromagnetic_forces D "electromagnetic forces" BT force RT electromagnetic_field ## electromagnetic_interaction electromagnetic_interaction D "electromagnetic interaction" BT interaction ## electromagnetic_radiation electromagnetic_radiation ALT "electromagnetic wave" D "electromagnetic radiation" BT radiation wave NT Cerenkov_radiation X-ray_radiation black_body_radiation bremsstrahlung continuum_radiation cyclotron_radiation gamma-ray_radiation infrared_radiation microwave_radiation millimeter_radiation polarized_light polarized_radiation radio_radiation submillimeter_radiation synchrotron_radiation thermal_radiation ultraviolet_radiation visible_radiation RT Planck_black_body_formula color darkness effective_temperature electrostatic_wave flux_density gravitational_lensing lamp light_absorption light_interference light_polarization light_scattering luminescence photon radiative_equilibrium recombination_line refraction solar_constant wavelength CN "FVH+ES: moved radiation to BT, lots of NT and RT from electromagnetic_wave (2007-OCT-8)" ## electromagnetic_theory electromagnetic_theory D "electromagnetic theory" NT cosmic_electrodynamics ## electron_beam electron_beam D "electron beam" NT relativistic_electron ## electron_density electron_density D "electron density" BT density RT electron ## electronic_camera electronic_camera D "electronic camera" NT electronographic_camera RT image_tube ## electronic_equipment electronic_equipment D "electronic equipment" NT diode RT instrument shot_noise ## electronics electronics D "electronics" N "combine with other terms" ## electronographic_camera electronographic_camera ALT "electrographic camera" D "electronographic camera" BT electronic_camera ## electron_pumping electron_pumping D "electron pumping" RT laser maser ## electron electron D "electron" BT fundamental_particle lepton nuclear_radiation particle RT Compton_effect Compton_scattering alpha_particle bremsstrahlung electron_density inverse_Compton_effect inverse_Compton_scattering pair_annihilation pair_production photoionization positron radiative_recombination radioactivity recombination thermionic_emission ## electron_temperature electron_temperature D "electron temperature" BT temperature HN "APM: new (2007-OCT-4)" ## electrostatic_wave electrostatic_wave D "electrostatic wave" RT electric_charge electric_field electromagnetic_radiation radiation_scattering ## elementary_particle_scattering elementary_particle_scattering D "elementary particle scattering" BT scattering RT radiation_scattering ## elementary_particle elementary_particle D "elementary particle" BT particle NT antiparticle axion baryon boson graviton hadron lepton meson neutrino neutron proton photon pion quark RT Dark_Matter Feynman_diagram particle_acceleration particle_creation particle_escape particle_interaction particle_production plasma N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## element_formation element_formation ALT "formation of element" D "element formation" RT abundance chemical_element frozen_in_element origin ## ellipsoidal_variable_star ellipsoidal_variable_star ALT "ellipsoidal binary star" "photometric binary star" D "ellipsoidal variable star" BT binary_star close_binary_star contact_binary_star variable_star NT beta_Lyrae_star RT eclipsing_binary_star spectroscopic_binary_star ## elliptical_galaxy elliptical_galaxy ALT "e galaxy" D "elliptical galaxy" BT galaxy NT D_galaxy E_galaxy Ep_galaxy cD_galaxy giant_elliptical_galaxy RT Faber-Jackson_relation SBF_distance fundamental_plane oblateness ## elliptical_orbit elliptical_orbit ALT "eccentric orbit" D "elliptical orbit" BT orbit periodic_orbit NT circular_orbit RT annual_equation eccentricity equation_of_time hyperbolic_orbit parabolic_orbit ## emerging_flux emerging_flux D "emerging flux" BT magnetic_field RT solar_activity sunspot HN "FVH: new (2007-OCT-29)" ## emission_coefficient emission_coefficient D "emission coefficient" RT Einstein_coefficient ## emission_line_galaxy emission_line_galaxy D "emission line galaxy" BT emission_line_object galaxy peculiar_galaxy NT Markarian_galaxy Seyfert_nucleus liner_galaxy RT H_II_region Haro_galaxy Seyfert_galaxy active_galactic_nucleus active_galaxy emission_line ## emission_line_object emission_line_object D "emission line object" NT H_II_region Herbig-Haro_object emission_line_galaxy emission_line_star emission_nebula RT emission_line N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## emission_line emission_line D "emission line" BT spectral_line NT Ca_II_emission_line X-ray_line coronal_line forbidden_line recombination_line RT H_II_region Neumann_line atomic_process emission_line_galaxy emission_line_object emission_line_star emission_nebula emission_process emission_spectrum flash_spectrum line_formation line_identification line_intensitite line_profile line_ratio spectrum spectroscopic_analysis ## emission_line_star emission_line_star D "emission line star" BT active_star emission_line_object NT Me_star Me_variable_star Mira_variable_star RV_Tauri_star RW_Aurigae_star S_Doradus_star T_Tauri_star X-ray_star Z_Andromedae_star early-type_emission_star flare_star flash_star gamma_Cassiopeiae_star symbiotic_star RT P_Cygni_line_profile U_Geminorum_star dwarf_nova emission_line peculiar_star planetary_nebula N "ES: deleted NT shell_star (2007-OCT-8)" ## emission_nebula emission_nebula D "emission nebula" BT emission_line_object gaseous_nebula nebula NT H_II_region Herbig-Haro_object planetary_nebula RT T_Tauri_star emission_line ## emission_process emission_process D "emission process" RT emission_line emission_spectrum ## emission_spectrum emission_spectrum D "emission spectrum" BT line_spectrum spectrum NT C_I_emission OH_emission X-ray_emission free-bound_emission free-free_emission infrared_emission microwave_emission radio_emission thermal_emission RT H_I_emission Neumann_line Raman_effect emission_line emission_process light_emission ## emissivity emissivity D "emissivity" RT black_body_radiation radiation temperature ## encounter encounter D "encounter" NT galaxy_encounter RT galaxy_merger gravitational_interaction stellar_dynamics N "generally of star or galaxy" ## energetic_particle energetic_particle D "energetic particle" RT plasma ## energy_content energy_content D "energy content" N "combine with other terms" ## energy_density energy_density D "energy density" BT density RT Omega_Lambda Omega_parameter HN "FVH: new (2007-OCT-24)" ## energy_distribution energy_distribution D "energy distribution" N "combine with other terms" ## energy energy D "energy" NT gravitational_energy kinetic_energy potential_energy RT flux force N "combine with other terms" ## energy_level energy_level D "energy level" RT spectrum ## energy_source energy_source D "energy source" N "combine with other terms" ## energy_spectrum energy_spectrum D "energy spectrum" RT absorption_spectrum ## energy-transfer energy-transfer ALT "energy transfer" D "energy-transfer" NT heat-transfer radiative_transfer RT adiabatic_process conduction convection non-LTE_transfer radiation thermodynamic_equilibrium thermodynamics ## engineering engineering D "engineering" BT design scientific_field N "combine with other terms" ## English_mounting English_mounting D "English mounting" BT equatorial_mounting ## enrichment enrichment D "enrichment" BT chemical_evolution RT abundance HN "ES: new (2007-OCT-8)" ## enthalpy enthalpy D "enthalpy" RT thermodynamics ## entropy entropy D "entropy" RT thermodynamics ## envelope envelope D "envelope" RT comet convection N "combine with other terms" ## Ep_galaxy Ep_galaxy D "peculiar elliptical galaxy with dust absorption (modification of Yerkes classification scheme)" BT E_galaxy elliptical_galaxy peculiar_galaxy radio_galaxy RT Yerkes_classification ## ephemeral_active_region ephemeral_active_region D "ephemeral active region" RT solar_activity ## ephemeris ephemeris D "ephemeris" RT almanac calendar catalog fundamental_star nautical_almanac time ## ephemeris_time ephemeris_time D "ephemeris time" BT time RT Universal_Time civil_time mean_solar_time solar_day year ## epoch epoch D "epoch" NT Besselian_epoch Julian_epoch RT Julian_Date time ## e-process e-process D "e process" RT nuclear_fusion stellar_evolution supernova ## equation_of_state equation_of_state D "equation of state" RT atomic_process interaction HN "FVH: new (2007-OCT-8)" ## equation_of_the_center equation_of_the_center D "equation of the center" RT Earth-Moon_system Moon ## equation_of_the_equinox equation_of_the_equinox D "equation of the equinox" RT Earth_rotation equation_of_time equinox_position nutation precession sidereal_time ## equation_of_time equation_of_time D "equation of time" RT Earth_orbit elliptical_orbit equation_of_the_equinox mean_solar_time ## equator_correction equator_correction D "equator correction" RT celestial_equator ## equator_determination equator_determination D "equator determination" RT celestial_equator ## equator equator D "equator" RT Declination Right_Ascension celestial_pole N "of Earth; also see celestial equator" ## equatorial_bulge equatorial_bulge D "equatorial bulge" RT geoid oblateness planet rotation ## equatorial_coordinate_system equatorial_coordinate_system ALT "celestial coordinate" "equatorial system" D "equatorial coordinate system" BT celestial_coordinate_system NT celestial_equator celestial_pole Declination Right_Ascension RT equatorial_mounting equatorial_zone ## equatorial_mounting equatorial_mounting D "equatorial mounting" BT telescope_mounting NT English_mounting German_mounting fork_mounting horseshoe_mounting yoke_mounting RT altazimuth_mounting equatorial_coordinate_system ## equatorial_zone equatorial_zone D "equatorial zone" RT Declination equatorial_coordinate_system ## equator_position equator_position D "equator position" RT astrometry celestial_equator ## equilibrium equilibrium D "equilibrium" N "combine with other terms" ## equilibrium_figures equilibrium_figures D "equilibrium figures" RT model ## equinox_correction equinox_correction D "equinox correction" RT equinox_position ## equinox equinox D "equinox" NT autumnal_equinox mean_equinox vernal_equinox RT celestial_equator ecliptic solstice ## equinox_position equinox_position D "equinox position" RT equation_of_the_equinox equinox_correction ## equipotential_surface equipotential_surface D "equipotential surface" RT contact_binary_star ## equivalent_width equivalent_width D "equivalent width" BT line_width RT absorption instrumental_profile line_broadening spectrum spectral_line ## erbium erbium ALT "Er" D "erbium (atomic number 68)" BT fundamental_chemical_element rare_earth HN "FVH: new (2007-OCT-25)" ## e_region e_region D "e region" BT Kapteyn_selected_area RT Johnson_photometry Stromgren_photometry photometry ## ergosphere ergosphere D "ergosphere" RT black_hole event_horizon velocity_of_light ## error_analysis error_analysis D "error analysis" BT data_analysis RT data_processing data_reduction ## error error D "error" NT selection_effect RT correction N "combine with other terms" ## eruption eruption D "eruption" RT cataclysmic_variable_star eruptive_binary_star ## eruptive_binary_star eruptive_binary_star D "eruptive binary star" BT binary_star NT SX_Arietis_star X-ray_binary_star alpha2_Canum_Venaticorum_star cataclysmic_variable_star dwarf_nova nova symbiotic_star RT X-ray_source eruption interacting_binary_star mass_exchange mass-loss ## escape_velocity escape_velocity D "escape velocity" BT velocity RT orbital_velocity parabolic_velocity ## ethane ethane D "ethane" BT hydrocarbon ## ethylene ethylene D "ethylene" BT hydrocarbon ## europium europium ALT "Eu" D "europium (atomic number 63)" BT fundamental_chemical_element rare_earth HN "FVH: new (2007-OCT-25)" ## evaporation evaporation D "evaporation" N "combine with other terms" ## event_horizon event_horizon D "event horizon" RT Hawking_radiation black_hole ergosphere velocity_of_light ## Evershed-effect Evershed-effect ALT "Evershed effect" D "Evershed-effect" RT sunspot ## evolutionary_track evolutionary_track D "evolutionary track" NT Hayashi_track Henyey_track RT Hertzsprung-Russell_diagram stellar_evolution ## evolution evolution D "evolution" NT dynamical_evolution stellar_evolution RT galaxy planet N "combine with other terms" ## evolved_star evolved_star D "evolved star" BT non-main_sequence_star star NT horizontal_branch_star old_star planetary_nebula post-main_sequence_star pulsar white_dwarf RT red_giant_tip N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## excitation excitation D "excitation" RT atomic_process N "combine with other terms" ## exciting_star exciting_star D "exciting star" RT H_II_region planetary_nebula ## exosphere exosphere D "exosphere" RT Earth_atmosphere ionosphere magnetosphere planet thermosphere troposphere upper_atmosphere ## expanding_envelope expanding_envelope D "expanding envelope" BT circumstellar_envelope RT circumstellar_matter ## expanding_universe expanding_universe D "expanding universe" BT cosmology ## expansion expansion D "expansion" N "combine with other terms" ## explosion explosion D "explosion" N "combine with other terms" ## exponential_profile exponential_profile D "exponential mass-profile" BT mass_distribution RT Burkert_profile Navarro-Frenk-White_profile isothermal_sphere HN "FVH: new (2007-OCT-5)" ## extended_object extended_object D "extended object" RT extended_source three-dimensional_spectrum two-dimensional_spectrum ## extended_source extended_source D "extended source" BT radio_source source RT extended_object radio_structure ## extragalactic_object extragalactic_object D "extragalactic object" NT extragalactic_radio_source galaxy quasar N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## extragalactic_radio_source extragalactic_radio_source D "extragalactic radio source" BT extragalactic_object radio_source NT BL_Lacertae_object quasar radio_galaxy ## extrasolar_planet extrasolar_planet D "extrasolar planet" BT planet RT Solar_System star_formation ## extraterrestrial_intelligence extraterrestrial_intelligence D "extraterrestrial intelligence" BT extraterrestrial_life RT search_for_extraterrestrial_life CN "FVH: moved EXTRATERRESTRIAL_LIFE to BT (2007-OCT-1)" ## extraterrestrial_life extraterrestrial_life D "extraterrestrial life" BT life NT extraterrestrial_intelligence RT astrobiology interstellar_communication search_for_extraterrestrial_life CN "FVH: moved LIFE to BT, SETI to RT (2007-OCT-4)" ## extreme_carbon_star extreme_carbon_star D "extreme carbon star" BT giant infrared_source RT circumstellar_shell ## extreme_horizontal_branch_star extreme_horizontal_branch_star D "extreme horizontal branch star" BT horizontal_branch_star HN "ES: new (2007-OCT-8)" ## extreme_population_I_star extreme_population_I_star D "extreme population I star" BT population_I_star ## extreme_ultraviolet_radiation extreme_ultraviolet_radiation ALT "EUV" D "extreme ultraviolet radiation" BT ultraviolet_radiation RT far_ultraviolet_radiation near_ultraviolet_radiation ## eyepiece eyepiece D "eyepiece" NT Kellner_eyepiece Ramsden_eyepiece orthoscopic_eyepiece RT graticule lens optical_telescope reticle ## Faber-Jackson_distance Faber-Jackson_distance D "Faber-Jackson distance" BT distance_measurement RT Faber-Jackson_relation HN "ES: new (2007-OCT-8)" ## Faber-Jackson_relation Faber-Jackson_relation D "Faber-Jackson relation" BT fundamental_plane luminosity-dispersion_relation statistical_relation RT Faber-Jackson_distance elliptical_galaxy HN "FVH: new (2007-OCT-9)" ## Fabry-Perot_interferometer Fabry-Perot_interferometer ALT "Fabry Perot interferometer" D "Fabry-Perot interferometer" BT interferometer ## Fabry-Perot_spectrograph Fabry-Perot_spectrograph ALT "Fabry Perot spectrograph" "Fabry Perot spectrometer" "Fabry-Perot spectrometer" D "Fabry-Perot spectrograph" BT spectrograph ## facula facula D "facula" RT chromosphere granulation photosphere plage ## faint_blue_star faint_blue_star D "faint blue star" BT early-type_star faint_star ## faint_galaxy faint_galaxy D "faint galaxy" BT galaxy N "combine with other terms" ## faint_star faint_star D "faint star" BT star NT faint_blue_star N "combine with other terms" ## false_color_photography false_color_photography D "false color photography" BT photography ## Fanaroff-Riley_class Fanaroff-Riley_class D "fanaroff riley class" RT galaxy radio_galaxy ## Faraday_effect Faraday_effect D "Faraday effect" "Faraday rotation" BT magneto-optical_effect RT H_II_region light_polarization polarized_radiation ## far_infrared_radiation far_infrared_radiation D "far infrared radiation" BT infrared_radiation RT M_magnitude N_magnitude O_magnitude P_magnitude Q_magnitude infrared_photometry near_infrared_radiation ## far_ultraviolet_radiation far_ultraviolet_radiation ALT "FUV" D "far ultraviolet radiation" BT ultraviolet_radiation RT extreme_ultraviolet_radiation near_ultraviolet_radiation ## fast_Fourier_transform fast_Fourier_transform ALT "FFT" D "fast Fourier transform" BT Fourier_transform ## fast_nova fast_nova D "fast nova" BT nova RT recurrent_nova slow_nova ## F_corona F_corona ALT "F component" "F-corona" D "F corona" BT corona RT zodiacal_light ## F_dwarf F_dwarf D "F dwarf star" BT F_star dwarf ## feed_horn feed_horn D "feed horn" RT antenna feed horn_antenna radio_telescope telescope_instrument ## feed feed D "feed" RT feed_horn telescope_instrument ## Fermi-Dirac_nucleus Fermi-Dirac_nucleus ALT "Fermi Dirac nucleus" D "Fermi-Dirac nucleus" BT nucleus_atom RT Bose-Einstein_nucleus Fermi-Dirac_statistics ## Fermi-Dirac_statistics Fermi-Dirac_statistics ALT "Fermi Dirac statistics" D "Fermi-Dirac statistics" RT Bose-Einstein_statistics Fermi-Dirac_nucleus quantum_mechanics ## Fermi_interaction Fermi_interaction D "Fermi interaction" BT weak_interaction ## fermion fermion D "fermion" BT fundamental_particle RT boson ## fermium fermium ALT "Fm" D "fermium (atomic number 100)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Feynman_diagram Feynman_diagram D "Feynman diagram" RT elementary_particle ## Feynman_integrals Feynman_integrals D "Feynman integrals" ## F_giant F_giant D "F giant star" BT F_star giant ## fiber_optics fiber_optics D "fiber optics" BT optics RT optical_fiber ## fibrill fibrill D "fibrill" RT chromosphere ## field_corrector field_corrector ALT "correcting lens" D "field corrector" BT lens optical_component RT catadioptric_system corrector_plate focal_reducer optical_instrument ## field_curvature field_curvature ALT "curvature of field" D "field curvature" BT optical_aberration RT astigmatism chromatic_aberration comatic_aberration distortion optical_system spherical_aberration ## field_equation field_equation D "field equation" RT electromagnetic_field relativity ## field_galaxy field_galaxy D "field galaxy" BT galaxy N "generally, foreground or background object" ## field_of_view field_of_view D "field of view" RT vignetting N "at telescope' foci" ## field_star field_star D "field star" BT source star N "generally, foreground or background object" ## figuring figuring D "figuring" BT polishing RT Hartmann_test lens mirror optical_surface optical_testing N "polishing optics to accurate shape" ## filamentary_nebula filamentary_nebula D "filamentary nebula" BT nebula RT nebular_filament ## filling_factor filling_factor D "filling factor" RT telescope_array ## filter filter D "filter" NT interference_filter neutral_density_filter optical_filter RT attenuation filter_wheel CN "FVH: added NT NEUTRAL_DENSITY_FILTERS (2007-SEP-21)" ## filter_wheel filter_wheel D "filter wheel" RT camera filter HN "FVH: new (2007-SEP-21)" ## finding_chart finding_chart D "finding chart" RT atlas map sky_survey star_atlas ## finding_list finding_list D "finding list" RT catalog ## fine_analysis fine_analysis D "fine analysis" BT analysis RT data_reduction ## fine_structure fine_structure D "fine structure" RT molecular_line spectral_line ## fireball fireball D "fireball" BT meteor RT bolide ## fission fission D "fission" NT nuclear_fission ## FK_catalog_system FK_catalog_system D "FK catalog system" RT catalog ## flare flare ALT "chromospheric eruption" D "flare" NT X-ray_flare optical_flare outburst radio_flare RT Sun active_Sun burst prominence solar_activity solar_filament ## flare_star flare_star D "flare star" BT dwarf emission_line_star infrared_source radio_star NT BY_Draconis_star UV_Ceti_star red_dwarf_flare_star RT T_association flash_star optical_flare optical_outburst radio_flare ## flash_spectrum flash_spectrum D "flash spectrum" RT chromosphere emission_line solar_eclipse ## flash_star flash_star D "flash star" BT emission_line_star pre-main_sequence_star RT T_association UV_Ceti_star flare_star ## flat_field_lamp flat_field_lamp D "flat field lamp" BT lamp RT calibration camera spectrograph HN "FVH: new (2007-SEP-21)" ## flat_field flat_field D "flat field" RT image_processing two-dimensional_detector ## flattening flattening D "flattening" N "combine with other terms" ## F_layer F_layer ALT "F region" D "F layer" RT Earth_atmosphere ionosphere N "Earth upper atmosphere" ## flexure flexure D "flexure" N "combine with other terms" ## florine florine ALT "F" D "florine (atomic number 9)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## flow flow D "flow" NT non-equilibrium_flow RT fluid_dynamics N "combine with other terms" ## flow_instability flow_instability D "flow instability" RT non-equilibrium_flow ## fluctuation fluctuation D "fluctuation" N "combine with other terms" ## fluid_dynamics fluid_dynamics D "fluid dynamics" BT fluid_mechanics NT gas_dynamics hydrodynamics relativistic_fluid_dynamics RT flow mass-transfer ## fluid_mechanics fluid_mechanics D "fluid mechanics" BT scientific_field NT fluid_dynamics RT Rayleigh-Taylor_instability ## fluorescence fluorescence D "fluorescence" NT X-ray_fluorescence RT luminescence photoluminescence spectrum ## flux_density flux_density D "flux density" RT electromagnetic_radiation luminosity radiation ## flux flux D "flux" RT energy luminosity N "combine with other terms" ## focal_length focal_length D "focal length" RT focal_reducer focus ## focal_reducer focal_reducer D "focal reducer" RT field_corrector focal_length ## focus focus D "focus" NT Cassegrain_focus Coude_focus Nasmyth_focus Newtonian_focus prime_focus RT focal_length optical_aberration telescope ## Fokker-Planck_equation Fokker-Planck_equation ALT "Fokker Planck equation" D "Fokker-Planck equation" RT stellar_dynamics ## forbidden_line forbidden_line D "forbidden line" BT emission_line RT forbidden_transition nebula spectrum ## forbidden_transition forbidden_transition D "forbidden transition" RT forbidden_line nebula spectrum ## forbush_effect forbush_effect D "forbush effect" RT cosmic_ray solar_physics ## force force D "force" NT centrifugal_force centripetal_force electromagnetic_forces gravitational_force RT electric_field energy magnetic_field N "combine with other terms" ## forecasts forecasts D "forecasts" RT prediction N "combine with other terms" ## fork_mounting fork_mounting D "fork mounting" BT equatorial_mounting ## formation formation D "formation" N "combine with other terms" ## Fourier_analysis Fourier_analysis ALT "harmonic analysis" D "Fourier analysis" RT Fourier_component Fourier_transform fundamental_frequency harmonic_frequency maximum_entropy_method multi-periodic_pulsation overtone_frequency waveform_analysis ## Fourier_component Fourier_component D "Fourier component" RT Fourier_analysis harmonic_frequency ## Fourier_spectrograph Fourier_spectrograph ALT "Fourier spectrometer" D "Fourier spectrograph" BT spectrograph ## Fourier_transform Fourier_transform D "Fourier transform" NT fast_Fourier_transform RT Fourier_analysis ## Fourier_transform_spectroscopy Fourier_transform_spectroscopy D "Fourier transform spectroscopy" BT spectroscopy ## fragmentation fragmentation D "fragmentation" N "combine with other terms" ## fragment fragment D "fragment" N "combine with other terms" ## francium francium ALT "Fr" D "francium (atomic number 87)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Fraunhofer_line Fraunhofer_line D "Fraunhofer line" BT spectral_line NT B_band G_band H_line K_line RT Sun absorption_spectrum N "not a complete list of terms" ## free-bound_emission free-bound_emission ALT "free bound emission" D "free-bound emission" BT emission_spectrum radiation_mechanism ## free-free_emission free-free_emission ALT "free free emission" D "free-free emission" BT emission_spectrum radiation_mechanism RT spectrum thermal_emission ## f_region f_region D "f region" BT Kapteyn_selected_area RT Johnson_photometry Stromgren_photometry photometry ## frequency_analysis frequency_analysis D "frequency analysis" RT maximum_entropy_method multi-periodic_pulsation ## frequency_distribution frequency_distribution D "frequency distribution" RT Hess_diagram distribution_function ## frequency frequency D "frequency" RT wavelength N "combine with other terms" ## frequency_shift frequency_shift D "frequency shift" NT glitch RT blueshift pulsar redshift ## frequency_standard frequency_standard D "frequency standard" RT instrument ## friction friction D "friction" NT dynamical_friction ## Friedmann_universe Friedmann_universe D "Friedmann universe" BT cosmology RT Big_Bang_theory oscillating_universe ## frozen_in_element frozen_in_element D "frozen in element" RT element_formation supernova ## F_star F_star D "F star" BT intermediate_type_star NT F_dwarf F_giant F_subdwarf F_subgiant F_supergiant RT spectral_type ## F_subdwarf F_subdwarf D "F subdwarf star" BT F_star subdwarf ## F_subgiant F_subgiant D "F subgiant star" BT F_star subgiant ## F_supergiant F_supergiant D "F supergiant star" BT F_star supergiant NT UU_Herculis_star ## function function D "function" NT distribution_function N "in mathematics" ## fundamental_chemical_element fundamental_chemical_element D "the fundamental chemical element which appear in the periodic table" BT atom chemical_element NT actinium aluminum americium antimony argon arsenic astatine barium berkelium beryllium bismuth bohrium boron bromine cadmium caesium calcium californium carbon cerium chlorine chromium cobalt copper curium darmtadtium dubnium dysprosium einsteinium erbium europium fermium florine francium gadolinium gallium germanium gold hafnium hassium helium holmium hydrogen indium iodine iridium iron krypton lanthanum lawrencium lead lithium lutetium magnesium manganese meitnerium mendelevium mercury molybdenum neodymium neon neptunium nickel niobium nitrogen nobelium osmium oxygen palladium phosphorus platinum plutonium polonium potassium praseodymium promethium protactinium radium radon rare_earth rhenium rhodium roentgenium rubidium ruthenium rutherfordium samarium scandium seaborgium selenium silicon silver sodium strontium sulfur tantalum technetium tellurium terbium thallium thorium thulium tin titanium tungsten uranium vanadium xenon ytterbium yttrium zinc zirconium HN "FVH: new (2007-OCT-25)" ## fundamental_frequency fundamental_frequency D "fundamental frequency" RT Fourier_analysis fundamental_mode harmonic_frequency overtone_frequency variable_star ## fundamental_mode fundamental_mode D "fundamental mode" BT pulsation_mode RT fundamental_frequency overtone_mode ## fundamental_particle fundamental_particle D "fundamental particle" BT particle NT electron fermion neutron proton ## fundamental_plane fundamental_plane D "fundamental plane" BT luminosity-dispersion_relation radius-luminosity_relation NT Faber-Jackson_relation RT elliptical_galaxy HN "FVH: new (2007-OCT-9)" ## fundamental_star fundamental_star D "fundamental star" BT star RT astrometry catalog ephemeris ## fundamental_system fundamental_system D "fundamental system" RT position N "combine with other terms" ## funneling funneling D "funneling" RT late-type_giant stellar_evolution ## FU_Orionis_star FU_Orionis_star D "fu orionis star" BT T_Tauri_star infrared_source RT T_association mass-loss ## fusion fusion D "fusion" NT nuclear_fusion ## future_light_cone future_light_cone D "future light cone" BT light_cone RT past_light_cone ## gadolinium gadolinium ALT "Gd" D "gadolinium (atomic number 64)" BT fundamental_chemical_element rare_earth HN "FVH: new (2007-OCT-25)" ## Galactic Galactic D "Galactic" N "FVH: WARNING: usage is not consistent when combined within tokens, e.g. galactic_nucleus (the MW has only one!), so capitalized (2007-OCT-5)" "IAU: used as an adjective only for Milky Way property see also galaxy" ## Galactic_anticenter Galactic_anticenter ALT "anticenter" D "Galactic anticenter" RT Galactic_coordinate_system Milky_Way_galaxy CN "FVH: capitalized, since only refers to MW (2007-OCT-5)" ## Galactic_bulge Galactic_bulge D "Galactic bulge (Milky Way)" BT bulge RT Galactic_center Galactic_plane Galactic_structure Milky_Way_galaxy CN "FVH: capitalized, since only refers to MW; added BT bulge (2007-OCT-5)" ## Galactic_center Galactic_center D "Galactic center (Milky Way)" BT galactic_nucleus RT Galactic_bulge Galactic_coordinate_system Galactic_structure Milky_Way_galaxy CN "FVH: capitalized, since only refers to MW; added BT galactic_nucleus (2007-OCT-5)" ## Galactic_cluster Galactic_cluster D "Galactic open star cluster (in Milky Way)" BT open_star_cluster RT Milky_Way_galaxy CN "FVH: capitalized, since only refers to MW (2007-OCT-5)" ## Galactic_coordinate_system Galactic_coordinate_system D "Galactic coordinate system" BT celestial_coordinate_system RT Galactic_anticenter Galactic_center Galactic_latitude Galactic_longitude Galactic_pole Milky_Way_galaxy CN "FVH: capitalized, since only refers to MW (2007-OCT-5)" ## Galactic_cosmic_ray Galactic_cosmic_ray D "Galactic cosmic ray" BT cosmic_ray RT Milky_Way_galaxy CN "FVH: capitalized, since only refers to MW; moved cosmic_ray to BT (2007-OCT-5)" ## Galactic_equator Galactic_equator D "Galactic equator" RT Galactic_latitude Galactic_longitude Galactic_pole Milky_Way_galaxy CN "FVH: capitalized, since only refers to MW (2007-OCT-5)" ## Galactic_halo Galactic_halo D "Galactic halo" BT halo RT Galactic_structure Milky_Way_galaxy RR_Lyrae_star globular_star_cluster halo_star population_II_star population_III_star CN "FVH: added RT POPULATION_III_STARS (2007-SEP-21)" "FVH: capitalized, since only refers to MW (2007-OCT-5)" ## Galactic_latitude Galactic_latitude D "Galactic latitude" BT latitude RT Galactic_coordinate_system Galactic_equator Galactic_longitude Galactic_plane Galactic_pole Milky_Way_galaxy CN "FVH: capitalized, since only refers to MW; moved latitude to BT (2007-OCT-5)" ## Galactic_longitude Galactic_longitude D "Galactic longitude" BT longitude RT Galactic_coordinate_system Galactic_equator Galactic_latitude Galactic_pole Milky_Way_galaxy CN "FVH: capitalized, since only refers to MW; moved longitude to BT (2007-OCT-5)" ## galactic_nucleus galactic_nucleus D "galactic nucleus" BT nucleus_celestial_object NT Galactic_center active_galactic_nucleus compact_nucleus RT Galactic_structure N_galaxy black_hole galaxy_structure massive_object population_II_star ## Galactic_plane Galactic_plane D "Galactic plane (Milky Way)" RT Galactic_bulge Galactic_latitude Galactic_pole Galactic_window Milky_Way_galaxy disk_population disk_star CN "FVH: capitalized, since only refers to MW (2007-OCT-5)" ## Galactic_pole Galactic_pole D "Galactic pole (Milky Way)" BT pole NT North_Galactic_Pole South_Galactic_Pole RT Galactic_coordinate_system Galactic_equator Galactic_latitude Galactic_longitude Galactic_plane Galactic_spurs Milky_Way_galaxy CN "FVH: capitalized, since only refers to MW (2007-OCT-5)" ## Galactic_rotation Galactic_rotation D "Galactic rotation (Milky Way)" BT galaxy_rotation_curve rotation RT Dark_Matter Milky_Way_galaxy Oort_constant Oort_formulae cosmic_year differential_rotation high-velocity_cloud high-velocity_star kinematics proper_motion space_motion stellar_dynamics CN "FVH: capitalized, since only refers to MW (2007-OCT-5)" "see galaxy_rotation_curve for external galaxy" ## Galactic_spurs Galactic_spurs D "Galactic spurs (Milky Way)" RT Galactic_pole Galactic_structure CN "FVH: capitalized, since only refers to MW (2007-OCT-5)" ## Galactic_structure Galactic_structure D "Galactic structure (Milky Way)" BT galaxy_structure RT Galactic_bulge Galactic_center Galactic_halo Galactic_spurs Oort_constant Oort_formulae galactic_nucleus kinematics pitch_angle spiral_arm star_count CN "FVH: capitalized, since only refers to MW; added BT galaxy_structure (2007-OCT-5)" N "See galaxy_structure for generic term (2007-OCT-5; FVH)" ## Galactic_window Galactic_window D "Galactic window (Milky Way)" BT window RT Galactic_plane interstellar_absorption CN "FVH: capitalized, since only refers to MW (2007-OCT-5)" "direction of low absorption" ## galaxy galaxy D "galaxy" BT extragalactic_object rotating_body NT BL_Lacertae_object D_galaxy Haro_galaxy L_galaxy Magellanic_cloud Milky_Way_galaxy N_galaxy active_galaxy barred_spiral_galaxy bipolar_galaxy blue_galaxy bright_galaxy companion_galaxy disk_galaxy double_galaxy dwarf_galaxy early-type_galaxy elliptical_galaxy emission_line_galaxy faint_galaxy field_galaxy giant_galaxy head_tail_galaxy hypergalaxy infrared_galaxy interacting_galaxy irregular_galaxy late-type_galaxy lenticular_galaxy massive_galaxy multiple_galaxy nearby_galaxy peculiar_galaxy primordial_galaxy protogalaxy radio_galaxy ring_galaxy spiral_galaxy starburst_galaxy RT Fanaroff-Riley_class Holmberg_radius Hubble_classification Hubble_diagram Tully-Fisher_relation Yerkes_classification active_galactic_nucleus collision coma cooling_flow differential_rotation edge_effect evolution galaxy_structure halo integrated_magnitude isophotal_diameter Local_Supercluster luminosity_function mass_distribution mass_to_light_ratio origin quasar_galaxy_pair surface_photometry velocity_field ## galaxy_cluster galaxy_cluster ALT "cluster of galaxies" "galaxy clustering" D "cluster of galaxies" BT cluster NT Abell_cluster Local_Supercluster RT Great_Attractor Sunyaev-Zeldovich_effect cD_galaxy clustering galaxy_count galaxy_distribution galaxy_merger intergalactic_matter intracluster_matter luminosity_function luminous_arc mass_distribution massive_galaxy missing_mass multiple_galaxy protocluster relaxation_time supercluster supergalactic_coordinate_system velocity_dispersion velocity_distribution virial_theorem ## galaxy_content galaxy_content D "galaxy content" N "combine with other terms" ## galaxy_count galaxy_count D "galaxy count" RT Dark_Energy cosmology galaxy_cluster galaxy_distribution observational_cosmology ## galaxy_distribution galaxy_distribution D "galaxy distribution" RT Dark_Energy cosmology galaxy_cluster galaxy_count observational_cosmology ## galaxy_encounter galaxy_encounter D "galaxy encounter" BT encounter RT galaxy_merger interacting_galaxy radio_source ## galaxy_evolution galaxy_evolution D "galaxy evolution" RT cosmology ## galaxy_formation galaxy_formation ALT "formation of galaxies" D "galaxy formation" ## galaxy_group galaxy_group D "group of galaxies" NT Hickson_compact_group Local_Group RT companion_galaxy multiple_galaxy ## galaxy_merger galaxy_merger D "galaxy merger" BT merger RT double_galaxy encounter galaxy_cluster galaxy_encounter interacting_galaxy ## galaxy_rotation_curve galaxy_rotation_curve D "rotation curve of galaxy" BT rotation NT Galactic_rotation RT Dark_Matter differential_rotation galaxy_structure kinematics mass_distribution stellar_dynamics CN "FVH: since Galactic_rotation only refers to MW (2007-OCT-5)" ## galaxy_structure galaxy_structure ALT "content of galaxy" "structure of galaxy" D "structure of galaxy" BT structure NT Galactic_structure RT bulge galactic_nucleus galaxy galaxy_rotation_curve halo interstellar_matter kinematics mass_distribution pitch_angle spiral_arm CN "FVH: new, since Galactic_structure only refers to Milky Way; moved content_of_galaxy to ALT (2007-OCT-5)" "FVH: renamed galaxy_structure to remove _of_ (2007-OCT-24)" ## galaxy_void galaxy_void D "galaxy void" RT blank_field intergalactic_space ## galilean_satellite galilean_satellite D "galilean satellite" BT satellite RT planet ## gallium gallium ALT "Ga" D "gallium (atomic number 31)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## gamma_Cassiopeiae_star gamma_Cassiopeiae_star D "gamma Cassiopeiae star" BT B_dwarf emission_line_star irregular_variable_star shell_star ## gamma-ray_astronomy gamma-ray_astronomy ALT "gamma ray astronomy" D "gamma-ray astronomy" BT space_astronomy RT balloon-borne_instrument rocket-borne_instrument satellite-borne_instrument ## gamma-ray_background gamma-ray_background ALT "gamma ray background" D "gamma-ray background" BT background_radiation RT X-ray_background gamma-ray_radiation microwave_background radio_background ultraviolet_background ## gamma-ray_burst gamma-ray_burst ALT "GRB" "cosmic gamma ray burst" "cosmic gamma-ray burst" "gamma ray burst" D "gamma-ray burst" BT burst RT X-ray_burst burster gamma-ray_source hypernova optical_burst radio_burst rapid_burst ## gamma-ray_line gamma-ray_line ALT "gamma ray line" D "gamma-ray line" BT gamma-ray_radiation CN "FVH: moved RT gamma-ray to BT gamma-ray_radiation (2007-OCT-8)" ## gamma-ray_observatory gamma-ray_observatory ALT "gamma ray observatory" D "gamma-ray observatory" BT observatory space_observatory RT gamma-ray_telescope N "see observatory for more rts" ## gamma-ray_radiation gamma-ray_radiation ALT "gamma radiation" "gamma-ray" D "gamma-ray radiation" BT electromagnetic_radiation high-energy_radiation nuclear_radiation radiation NT gamma-ray_line RT Cerenkov_radiation gamma-ray_background gamma-ray_scattering gamma-ray_source gamma-ray_spectrum pair_annihilation pair_production radioactivity ## gamma-ray_scattering gamma-ray_scattering ALT "gamma ray scattering" D "gamma-ray scattering" BT scattering RT gamma-ray_radiation ## gamma-ray_source gamma-ray_source ALT "gamma ray source" D "gamma-ray source" BT source NT soft_gamma-ray_repeater RT gamma-ray_burst gamma-ray_radiation optical_identification ## gamma-ray_spectrum gamma-ray_spectrum ALT "gamma ray spectrum" D "gamma-ray spectrum" RT gamma-ray_radiation gamma-ray_spectroscopy ## gamma-ray_spectrograph gamma-ray_spectrograph ALT "gamma ray spectrograph" D "gamma-ray spectrograph" BT spectrograph ## gamma-ray_spectroscopy gamma-ray_spectroscopy D "gamma-ray spectroscopy" BT spectroscopy RT gamma-ray_spectrum ## gamma-ray_telescope gamma-ray_telescope D "gamma-ray telescope" BT space_telescope telescope RT gamma-ray_observatory ## gas_cloud gas_cloud D "gas cloud" BT cloud ## gas_content gas_content D "gas content" RT gas ## gas_density gas_density D "gas density" BT density RT gas optical_depth ## gas_distribution gas_distribution D "gas distribution" RT gas spiral_arm ## gas_dynamics gas_dynamics ALT "gas kinematics" D "gas dynamics" BT fluid_dynamics RT gas ## gaseous_disk gaseous_disk D "gaseous discs" UK "gaseous disk" BT disk RT disk_star gas ## gaseous_nebula gaseous_nebula D "gaseous nebula" BT nebula NT emission_nebula RT gas ## gaseous_sphere gaseous_sphere D "gaseous sphere" NT Stromgren_sphere protogalaxy protostar RT gas ## gas gas D "gas" NT air carbon_dioxide carbon_monoxide ionized_gas neutral_gas relativistic_plasma N "See also table of elements" "combine with other terms" RT gas_content gas_density gas_distribution gas_dynamics gas_to_dust_ratio gaseous_disk gaseous_nebula gaseous_sphere ## gas_to_dust_ratio gas_to_dust_ratio D "gas to dust ratio" RT dust gas interstellar_reddening reddening_law selective_absorption ## G_band G_band D "G-band" BT Fraunhofer_line molecular_band RT molecular_spectrum ## G_dwarf G_dwarf D "G dwarf star" BT G_star dwarf ## gegenschein gegenschein ALT "counterglow" D "gegenschein" RT interplanetary_matter night_sky_brightness zodiacal_dust zodiacal_light ## general_theory_of_relativity general_theory_of_relativity D "general theory of relativity" BT gravitation relativity NT special_theory_of_relativity RT Dark_Energy Newtonian_gravitation Schwarzschild_metric Schwarzschild_radius cosmology gravitational_effect gravitational_wave space space-time_curvature time ## Geneva_photometry Geneva_photometry ALT "ubvgri photometry" D "Geneva photometry" BT medium_band_photometry photometric_system RT Vilnius_photometry ## geocentric_orbit geocentric_orbit D "geocentric orbit" BT orbit ## geocorona geocorona D "geocorona" RT Earth ## geodesy geodesy D "geodesy" BT Earth_sciences NT astronomical_geodesy space_geodesy RT Earth atomic_clock geoid pendulum ## geoid geoid D "geoid" RT Earth equatorial_bulge geodesy ## geology geology D "geology" BT Earth_sciences NT petrology RT geophysical_observatory glaciology planetology planet surface_of_celestial_body ## geomagnetic_field geomagnetic_field D "geomagnetic field" BT magnetic_field ## geomagnetism geomagnetism D "geomagnetism" RT Earth continental_drift geophysical_observatory paleomagnetism planet ## geophysical_observatory geophysical_observatory D "geophysical observatory" BT observatory RT Earth_sciences geology geomagnetism N "see observatory for more rts" ## geophysics geophysics ALT "terrestrial physics" D "geophysics" BT Earth_sciences RT Earth continental_drift ## geostationary_satellite geostationary_satellite D "geostationary satellite" BT artificial_satellite ## germanium germanium ALT "Ge" D "germanium (atomic number 32)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## German_mounting German_mounting D "German mounting" BT equatorial_mounting ## gf_value gf_value D "gf value" RT g_value line_formation line_width log_g_value oscillator_strength transition_probability ## G_giant G_giant D "G giant star" BT G_star giant RT G_subgiant ## giant_branch giant_branch ALT "RGB" "red giant branch" D "giant branch" NT blue_loop red_giant_bump red_giant_clump red_giant_tip RT Hertzsprung_gap Hertzsprung-Russell_diagram instability_strip turnoff_point zero-age_horizontal_branch ## giant_branch_star giant_branch_star D "giant branch star" BT star RT horizontal_branch_star ## giant_elliptical_galaxy giant_elliptical_galaxy D "giant elliptical galaxy" BT elliptical_galaxy ## giant_galaxy giant_galaxy D "giant galaxy" BT galaxy NT cD_galaxy ## giant_molecular_cloud giant_molecular_cloud D "giant molecular cloud" BT molecular_cloud RT interstellar_molecule ## giant_planet giant_planet D "giant planet" BT planet ## giant_radio_galaxy giant_radio_galaxy D "giant radio galaxy" BT radio_galaxy RT N_galaxy cD_galaxy ## giant giant ALT "CS star" D "giant star" BT post-main_sequence_star NT A_giant B_giant CH_star CN_star F_giant G_giant Lb_variable_star M_giant OH_IR_star R_star S_star extreme_carbon_star late-type_giant peculiar_giant weak_G_band_star RT carbon_burning dredge_up lithium_star luminosity_classification stellar_evolution zirconium_star ## glaciology glaciology D "glaciology" BT Earth_sciences RT Earth geology ## glass glass D "glass" BT optical_material NT optical_glass RT lens mirror optical_fiber ## glitch glitch D "sudden frequency shift" BT frequency_shift RT pulsar HN "FVH: new (2007-OCT-8)" ## global_positioning_system global_positioning_system ALT "GPS" D "Global Positioning System" RT satellite time_signal time_standard time_synchronization ## globular_star_cluster globular_star_cluster D "globular star cluster" BT star_cluster RT Galactic_halo Oosterhoff_group RR_Lyrae_star differential_rotation halo_star horizontal_branch_star population_II_star population_III_star turnoff_point ## globule globule D "globule" BT interstellar_matter NT Bok_globule cometary_globule RT dark_nebula ## Goedel_universe Goedel_universe D "Goedel universe" BT cosmology ## gold gold ALT "Au" D "gold (atomic number 79)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Goulds_belt Goulds_belt D "Goulds belt" RT Milky_Way_galaxy star_association ## grading_function grading_function ALT "illumination function" D "grading function" RT aperture_synthesis ## grain grain D "grain" BT interstellar_matter NT interplanetary_grain RT interplanetary_dust interstellar_dust ## granulation granulation D "granulation" NT supergranulation RT Sun convection facula photosphere ## granule granule D "granule" RT Sun photosphere ## graphite graphite D "graphite" RT interplanetary_grain interstellar_dust ## graph graph D "graph" N "combine with other terms" ## graticule graticule D "graticule" RT eyepiece reticle ## grating_response grating_response D "grating response" RT array ## grating_ring grating_ring D "grating ring" RT aperture_synthesis ## grating_spectrograph grating_spectrograph D "grating spectrograph" BT spectrograph RT diffraction_grating prism_spectrograph ## gravimetry gravimetry D "gravimetry" RT acceleration ## gravitating_disk gravitating_disk D "gravitating discs" UK "gravitating disk" BT disk RT circumstellar_matter ## gravitational_collapse gravitational_collapse D "gravitational collapse" BT collapse RT Chandrasekhar_mass Chandrasekhar-Schoenberg_limit black_hole gravitation gravitational_energy supernova ## gravitational_constant gravitational_constant D "Newton's gravitational constant G" BT physical_constant RT Newtonian_gravitation ## gravitational_deflection gravitational_deflection D "gravitational deflection" RT Einstein_ring double_quasar gravitational_lensing ## gravitational_effect gravitational_effect D "gravitational effect" RT MOdified_Newtonian_Dynamics general_theory_of_relativity ## gravitational_energy gravitational_energy D "gravitational energy" BT energy RT gravitational_collapse ## gravitational_equilibrium gravitational_equilibrium D "gravitational equilibrium" RT stellar_evolution ## gravitational_field gravitational_field ALT "gravity field" D "gravitational field" RT Lagrangian_point Schwarzschild_metric quantum_field_theory ## gravitational_force gravitational_force ALT "force of gravity" D "gravitational force" BT force RT Eddington_limit MOdified_Newtonian_Dynamics Newtonian_gravitation gravitation surface_gravity ## gravitational_instability gravitational_instability D "gravitational instability" RT gravitation ## gravitational_interaction gravitational_interaction D "gravitational interaction" BT interaction RT encounter gravitation ## gravitational_lens gravitational_lens D "gravitational lens" CN "FVH: effectively new, since old IAU term moved to gravitational_lensing (2007-OCT-08)" N "refers to the lens themselves, not the lensing process (see gravitational_lensing)" ## gravitational_lensing gravitational_lensing D "gravitational lensing" NT gravitational_lensing_shear gravitational_microlensing strong_gravitational_lensing weak_gravitational_lensing RT Einstein_ring black_hole caustic_crossing caustic cusp_crossing cusp double_quasar electromagnetic_radiation gravitation gravitational_deflection gravitationally_lensed_source luminous_arc mass_distribution visible_radiation white_hole CN "FVH: removed RT white_hole, added NT gravitational_microlensing etc. (2007-OCT-8)" ## gravitational_lensing_shear gravitational_lensing_shear D "gravitational lensing shear" BT gravitational_lensing HN "FVH: new (2007-OCT-8)" ## gravitationally_lensed_source gravitationally_lensed_source D "gravitationally lensed source" BT source NT Einstein_ring double_quasar luminous_arc RT gravitational_lensing HN "FVH: new (2007-OCT-8)" ## gravitational_microlensing gravitational_microlensing ALT "microlensing" D "microlensing" BT gravitational_lensing NT planetary_microlensing quasar_microlensing CN "FVH: added gravitational_ as prefix; moved RT to BT gravitational_lensing (2007-OCT-8)" ## gravitational_radiation gravitational_radiation D "gravitational radiation" BT radiation RT gravitation radiation_mechanism ## gravitational_redshift gravitational_redshift D "gravitational redshift" BT redshift RT Einstein_effect gravitation ## gravitational_wave gravitational_wave D "gravitational wave" BT wave RT celestial_mechanics general_theory_of_relativity ## gravitation gravitation D "gravitation" NT MOdified_Newtonian_Dynamics Newtonian_gravitation general_theory_of_relativity RT Lagrangian_point Roche_limit celestial_mechanics gravitational_collapse gravitational_force gravitational_instability gravitational_interaction gravitational_lensing gravitational_radiation gravitational_redshift gravity mass perturbation_theory relativity virial_theorem ## graviton graviton D "graviton" BT elementary_particle ## gravity_anomaly gravity_anomaly D "gravity anomaly" BT anomaly RT magnetic_anomaly mascon ## gravity_darkening gravity_darkening D "gravity darkening" RT surface_brightness surface_gravity von_Zeipel_theorem ## gravity gravity ALT "acceleration of gravity" D "gravity" RT Jeans_length gravitation pendulum relativistic_astrophysics von_Zeipel_theorem ## gravity_wave gravity_wave D "gravity wave" BT wave RT acoustic_wave stellar_interior ## grazing_incidence grazing_incidence D "grazing incidence" N "combine with other terms" ## grazing_incidence_spectrograph grazing_incidence_spectrograph D "grazing incidence spectrograph" BT spectrograph NT X-ray_spectrograph ## grazing_incidence_telescope grazing_incidence_telescope D "grazing incidence telescope" BT telescope NT X-ray_telescope ## Great_Attractor Great_Attractor D "Great Attractor" RT galaxy_cluster Local_Supercluster ## greenhouse_effect greenhouse_effect D "greenhouse effect" RT atmosphere infrared_radiation planet pollution terrestrial_radiation ## Gregorian_calendar Gregorian_calendar D "Gregorian calendar" BT calendar RT Julian_calendar time ## Gregorian_telescope Gregorian_telescope D "Gregorian telescope" BT telescope ## grid grid D "grid" RT reseaux reticle ## grism grism D "grism" BT optical_component RT diffraction_grating prism spectrograph transmission_grating ## ground-based_astronomy ground-based_astronomy ALT "ground based astronomy" D "ground-based astronomy" BT astronomy RT airplane-borne_instrument balloon-borne_instrument rocket-borne_instrument satellite-borne_instrument space_probe_instrument space_telescope ## G_star G_star D "G star" BT intermediate_type_star NT G_dwarf G_giant G_subdwarf G_subgiant G_supergiant RT spectral_type ## G_subdwarf G_subdwarf D "G subdwarf star" BT G_star subdwarf ## G_subgiant G_subgiant D "G subgiant star" BT G_star subgiant RT G_giant ## G_supergiant G_supergiant D "G supergiant star" BT G_star supergiant ## guide_system guide_system D "guide system" BT instrument NT autoguider RT control_system quadrant_detector telescope ## Gunn_diode Gunn_diode D "Gunn diode" RT semiconductor_device ## Gunn_photometry Gunn_photometry ALT "Gunn g,r,i,z photometry" D "Gunn photometry" BT broad_band_photometry photometric_system HN "FVH: new (2007-SEP-21)" ## g_value g_value D "g value" NT log_g_value RT gf_value line_formation line_width oscillator_strength transition_probability ## gyrosynchrotron_radiation gyrosynchrotron_radiation D "gyrosynchrotron radiation" BT synchrotron_radiation ## hadron_barrier hadron_barrier D "hadron barrier" RT Big_Bang_theory ## hadron hadron D "hadron" BT elementary_particle RT boson ## hafnium hafnium ALT "Hf" D "hafnium (atomic number 72)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## halation halation D "halation" RT image photographic_emulsion turbidity ## half-wave_dipole half-wave_dipole ALT "half wave dipole" "halfwave dipole" D "half-wave dipole" BT dipole RT Yagi_antenna radio_telescope ## half-wave_plate half-wave_plate ALT "half wave plate" "halfwave plate" D "half-wave plate" RT plane_polarization quarter_wave_plate HN "FVH: new (2007-SEP-21)" ## halo halo D "halo" NT Galactic_halo RT comet corona galaxy galaxy_structure halo_star light_scattering ## halo_star halo_star D "halo star" BT population_II_star population_III_star star RT Galactic_halo globular_star_cluster halo stellar_population ## H_alpha H_alpha D "H alpha (656 nm)" BT Balmer_series resonance_line RT H_alpha_emission_line_star H_alpha_photometry ## H_alpha_emission_line_star H_alpha_emission_line_star D "h alpha emission line star" RT H_alpha RW_Aurigae_star T_association variable_star ## H_alpha_photometry H_alpha_photometry D "h alpha photometry" BT narrow_band_photometry RT H_alpha ## H_and_K_line H_and_K_line D "H and K line" BT calcium_line NT H_line K_line ## Hanle_effect Hanle_effect D "Hanle effect" RT Sun prominence ## Harman-Seaton_sequence Harman-Seaton_sequence ALT "Harman Seaton sequence" D "Harman-Seaton sequence" RT Hertzsprung-Russell_diagram planetary_nebula subdwarf ## harmonic_frequency harmonic_frequency ALT "harmonic overtones" "harmonics" D "harmonic frequency" RT Fourier_analysis Fourier_component fundamental_frequency overtone_frequency N "refers only to Fourier component of non-sinusoidal wave; see also overtone frequency" ## Haro_galaxy Haro_galaxy D "Haro galaxy" BT galaxy RT emission_line_galaxy ## Hartmann_test Hartmann_test D "Hartmann test" RT figuring image optical_instrument ## hassium hassium ALT "Hs" D "hassium (atomic number 108)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Hawking_radiation Hawking_radiation D "Hawking radiation" RT black_hole event_horizon ## Hayashi_track Hayashi_track D "Hayashi track" BT evolutionary_track RT Hertzsprung-Russell_diagram convection ## H_beta H_beta D "H beta (486 nm)" BT Balmer_series RT H_beta_photometry ## H_beta_photometry H_beta_photometry D "h beta photometry" BT narrow_band_photometry RT H_beta Stromgren_photometry ## HD_curve HD_curve D "HD curve" RT photography N "Hurter and Driffield curve" ## H_delta H_delta D "H delta (410 nm)" BT Balmer_series ## head_tail_galaxy head_tail_galaxy D "head tail galaxy" BT galaxy radio_galaxy radio_source RT radio_structure tail ## heat-transfer heat-transfer D "heat transfer" BT energy-transfer ## heavy_element heavy_element D "heavy element" BT chemical_element RT abundance ## heavy_metal_star heavy_metal_star D "heavy metal star" BT late-type_giant peculiar_star RT S_star barium_star zirconium_star ## He_I He_I D "neutral helium" BT helium neutral_gas ## height height ALT "elevation" D "altitude [height]" N "use altitude [angle] for angle ## He_II He_II D "once-ionized helium" BT helium ## He_III He_III D "twice-ionized helium" BT helium ## He_II_ionization_zone He_II_ionization_zone ALT "He+ ionisation zone UK" "He+ ionization zone" D "He II ionization zone" RT Cepheid ZZ_Ceti_star delta_Scuti_star kappa_mechanism pulsating_variable_star pulsation_theory radial_pulsation variable_star CN "FVH: replaced + with II for better parsing of token (2007-OCT-12)" ## heliocentric_correction heliocentric_correction D "heliocentric correction" RT Astronomical_Unit coordinate_system heliocentric_Julian_Date heliocentric_velocity N "correction of velocity and times to the Sun's position" ## heliocentric_Julian_Date heliocentric_Julian_Date ALT "H.J.D." "HJD" D "heliocentric Julian Date" BT Julian_Date RT heliocentric_correction ## heliocentric_orbit heliocentric_orbit D "heliocentric orbit" BT orbit ## heliocentric_velocity heliocentric_velocity D "heliocentric velocity" BT velocity RT heliocentric_correction ## heliograph heliograph D "heliograph" ## heliometer heliometer D "heliometer" BT measuring_instrument ## heliopause heliopause D "heliopause" RT solar_atmosphere solar_wind ## helioseismology helioseismology ALT "solar seismology" D "helioseismology" BT asteroseismology seismology RT solar_oscillation ## heliosphere heliosphere D "heliosphere" RT interplanetary_matter interstellar_gas solar_activity solar_atmosphere solar_wind ## heliostat heliostat D "heliostat" BT coelostat RT siderostat solar_telescope telescope_mounting ## helium_burning helium_burning D "helium burning" BT nuclear_fusion nucleosynthesis RT carbon_burning helium_flash helium_shell_flash hydrogen_burning inner_core oxygen_burning shell_burning silicon_burning stellar_evolution stellar_interior ## helium_flash helium_flash ALT "helium detonation" D "helium flash" RT carbon_flash helium_burning helium_shell_flash nuclear_fusion red_giant_tip ## helium helium ALT "He" D "helium (atomic number 2)" BT fundamental_chemical_element NT He_I He_II He_III HN "FVH: new (2007-OCT-25)" ## helium-poor_star helium-poor_star ALT "helium poor star" D "helium-poor star" BT star NT Bw_star RT abundance metal_abundance ## helium-rich_star helium-rich_star ALT "helium rich star" D "helium-rich star" BT star NT DB_star RT abundance metal_abundance CN "FVH: added NT DB_STARS (2007-OCT-1)" ## helium_shell_flash helium_shell_flash D "helium shell flash" RT helium_burning helium_flash nuclear_fusion ## Helmholtz-Kelvin_contraction Helmholtz-Kelvin_contraction ALT "Helmholtz Kelvin contraction" "Kelvin-Helmholtz contraction" D "Helmholtz-Kelvin contraction" RT Kelvin_timescale ## Henry_Draper_catalog Henry_Draper_catalog D "henry draper catalog" BT catalog RT Henry_Draper_system spectral_classification ## Henry_Draper_system Henry_Draper_system ALT "HD system" "Harvard classification" D "Henry-Draper system" BT spectral_classification RT Henry_Draper_catalog ## Henyey_track Henyey_track D "Henyey track" BT evolutionary_track RT Hertzsprung-Russell_diagram stellar_evolution ## H_epsilon H_epsilon D "H epsilon" BT Balmer_series ## Herbig_AeBe_star Herbig_AeBe_star ALT "Herbig Ae-Be star" "Herbig star" D "Herbig AeBe star" BT Ae_star Be_star NT Ae_star Be_star ## Herbig-Haro_object Herbig-Haro_object ALT "HH-object" D "Herbig-Haro object" BT emission_line_object emission_nebula infrared_source intrinsic_variable_star pre-main_sequence_star RT T_association T_Tauri_star protostar ## Hertzsprung_gap Hertzsprung_gap D "Hertzsprung gap" RT Hertzsprung-Russell_diagram giant_branch ## Hertzsprung-Russell_diagram Hertzsprung-Russell_diagram ALT "HR diagram" "Hertzsprung Russell diagram" D "Hertzsprung-Russell diagram" RT Harman-Seaton_sequence Hayashi_track Henyey_track Hertzsprung_gap Hess_diagram absolute_magnitude asymptotic_giant_branch color-luminosity_relation color-magnitude_relation evolutionary_track giant_branch instability_strip luminosity main_sequence post-asymptotic_giant_branch red_giant_tip spectrum stellar_evolution turnoff_point zero-age_horizontal_branch zero-age_main_sequence ## Hess_diagram Hess_diagram D "Hess diagram" RT Hertzsprung-Russell_diagram frequency_distribution ## heterodyne heterodyne D "heterodyne" RT interferometer spectroscopy N "combine with other terms" ## H_gamma H_gamma D "H gamma (434 nm)" BT Balmer_series ## H_I H_I ALT "neutral hydrogen" D "H I" BT hydrogen neutral_gas RT 21-cm_line H_I_absorption H_I_cloud H_I_content H_I_emission H_I_region ## H_I_absorption H_I_absorption D "H I absorption" RT 21-cm_line H_I H_I_cloud ## Hickson_compact_group Hickson_compact_group ALT "HCG" D "Hickson compact group of galaxies" BT galaxy_group HN "FVH: new (2007-OCT-8)" ## H_I_cloud H_I_cloud D "H I cloud" RT 21-cm_line H_I H_I_absorption ## H_I_content H_I_content D "H I content" RT 21-cm_line H_I ## H_I_emission H_I_emission D "H I emission" RT 21-cm_line H_I emission_spectrum ## hierarchical_cosmology hierarchical_cosmology D "hierarchical cosmology" BT cosmology ## high-energy_astrophysics high-energy_astrophysics ALT "high energy astrophysics" "high energy process" "high-energy process" D "high-energy astrophysics" BT astrophysics RT cosmic_ray_astronomy inverse_Compton_effect nuclear_astrophysics particle_beam ## high-energy_radiation high-energy_radiation ALT "high energy radiation" D "high-energy radiation" BT radiation NT X-ray_radiation cosmic_ray gamma-ray_radiation RT X-ray_luminosity ## high-luminosity_star high-luminosity_star ALT "high luminosity star" "luminous star" D "high-luminosity star" BT star NT bright_star luminous_blue_variable_star nova supergiant supernova ## high-mass_star high-mass_star D "high-mass star" BT star NT high-mass_X-ray_binary_star HN "FVH: new (2007-OCT-9)" ## high-mass_X-ray_binary_star high-mass_X-ray_binary_star D "high-mass X-ray binary star" BT X-ray_binary_star high-mass_star RT low-mass_X-ray_binary_star HN "ES: new (2007-OCT-8)" ## high-resolution_spectrum high-resolution_spectrum ALT "high dispersion spectrum" "high resolution spectrum" "high-dispersion spectrum" D "high-resolution spectrum" NT Coude_spectrum echelle_spectrum RT Coude_spectrograph echelle_spectrograph ## high-resolution_spectrosopy high-resolution_spectrosopy ALT "high dispersion spectroscopy" "high resolution spectrosopy" "high-dispersion spectroscopy" D "high-resolution spectrosopy" BT spectroscopy RT Coude_spectrograph echelle_spectrograph ## high-speed_photometer high-speed_photometer ALT "high speed photometer" D "high-speed photometer" BT photometer RT time-resolved_spectroscopy variable_star ## high-state high-state D "photometric high state of variable object" RT low-state outburst variability variable_source HN "FVH: new (2007-OCT-8)" ## high-temperature high-temperature ALT "high temperature" "hot" D "high-temperature" N "combine with other terms" ## high-velocity_cloud high-velocity_cloud ALT "HVC" "high velocity cloud" D "high-velocity cloud" BT cloud RT Galactic_rotation Milky_Way_galaxy high-velocity_star velocity CN "FVH: added ALT HVC (2007-SEP-21)" ## high-velocity_star high-velocity_star ALT "high velocity star" D "high-velocity star" BT star RT Galactic_rotation Milky_Way_galaxy high-velocity_cloud orbit runaway_star velocity ## H_II H_II ALT "ionized hydrogen" D "H II" BT hydrogen ionized_gas RT H_II_region ## H_II_region H_II_region ALT "HII region" D "H II region" BT emission_line_object emission_nebula interstellar_matter NT compact_H_II_region RT Bok_globule Faraday_effect H_II cometary_globule emission_line_galaxy emission_line exciting_star plasma radio_recombination_line young_star ## Hirayama_family Hirayama_family D "Hirayama family" BT minor_planet_family RT Apollo_group ## H_I_region H_I_region D "H I region" BT interstellar_matter RT 21-cm_line H_I neutral_gas radio_absorption radio_recombination_line ## history_of_astronomy history_of_astronomy D "history of astronomy" NT archaeoastronomy N "combine with other terms" ## H_line H_line D "H line" BT Fraunhofer_line H_and_K_line RT K_line ## H_magnitude H_magnitude D "H magnitude" BT apparent_magnitude RT infrared_photometry near_infrared_radiation ## Holmberg_radius Holmberg_radius D "Holmberg radius" RT galaxy ## holmium holmium ALT "Ho" D "holmium (atomic number 67)" BT fundamental_chemical_element rare_earth RT holmium_star HN "FVH: new (2007-OCT-25)" ## holmium_star holmium_star D "holmium star" BT Ap_star peculiar_star RT holmium ## Holtsmark_approximation Holtsmark_approximation D "Holtsmark approximation" RT plasma ## horizon_coordinate_system horizon_coordinate_system D "horizon coordinate system" BT coordinate_system RT altazimuth_mounting altitude_angle azimuth horizon meridian nadir zenith ## horizon horizon D "horizon" RT altitude_angle azimuth celestial_sphere horizon_coordinate_system ## horizontal_branch_star horizontal_branch_star D "horizontal branch star" BT evolved_star population_II_star NT extreme_horizontal_branch_star RT RR_Lyrae_star giant_branch_star globular_star_cluster ## horizontal_parallax horizontal_parallax D "horizontal parallax" BT diurnal_parallax ## horn_antenna horn_antenna ALT "horn antennas" D "horn antenna" BT antenna radio_waveguide RT feed_horn ## horseshoe_mounting horseshoe_mounting D "horseshoe mounting" BT equatorial_mounting ## hour_angle hour_angle ALT "HA" D "hour angle" RT Right_Ascension sidereal_time transit_time ## HST_photometry HST_photometry ALT "HST Fnnn[LMNW] photometry" "Hubble photometry" D "HST photometry" BT broad_band_photometry photometric_system RT Hubble_Space_Telescope HN "FVH: new (2007-SEP-21)" ## Hubble_classification Hubble_classification ALT "Hubble sequence" D "Hubble classification" RT galaxy ## Hubble_constant Hubble_constant D "Hubble constant" BT cosmological_parameter RT Hubble_time cosmological_distance_scale cosmology redshift_magnitude_relation ## Hubble_diagram Hubble_diagram D "Hubble diagram" BT statistical_relation RT cosmology galaxy redshift redshift_magnitude_relation ## Hubble_law Hubble_law D "Hubble law" BT statistical_relation RT Dark_Energy cosmology observational_cosmology redshift redshift_magnitude_relation ## Hubble_radius Hubble_radius D "Hubble radius" RT Big_Bang_theory cosmology ## Hubble_Sandage_variable_star Hubble_Sandage_variable_star ALT "H S variable star" "H-S variable star" D "Hubble-Sandage variable star" RT supergiant ## Hubble_Space_Telescope Hubble_Space_Telescope ALT "HST" D "Hubble Space Telescope" BT optical_observatory space_observatory ultraviolet_observatory RT HST_photometry HN "FVH: new, because of HST_photometry (2007-NOV-1)" ## Hubble_time Hubble_time D "Hubble time" RT Big_Bang_theory Hubble_constant age cosmology ## hydrated_carbon hydrated_carbon ALT "CH" D "CH molecule" BT carbon_compound hydrocarbon interstellar_molecule molecule CN "FVH: moved CH to ALT to conform to standard use in the thesaurus (2007-OCT-5)" ## hydrocarbon hydrocarbon D "hydrocarbon" NT CS ethane ethylene hydrated_carbon polycyclic_hydrocarbon ## hydrodynamics hydrodynamics D "hydrodynamics" BT fluid_dynamics RT jet magnetohydrodynamics ## hydrogen_burning hydrogen_burning D "hydrogen burning" BT nucleosynthesis NT carbon_nitrogen_cycle proton-proton_reaction RT Chandrasekhar_mass Chandrasekhar-Schoenberg_limit carbon_burning helium_burning hydrogen inner_core nuclear_fusion oxygen_burning shell_burning silicon_burning stellar_evolution stellar_interior ## hydrogen_deficient_star hydrogen_deficient_star D "hydrogen-deficient star" BT star NT AM_Canum_Venaticorum_star RT hydrogen metal_abundance ## hydrogen hydrogen ALT "H" D "hydrogen (atomic number 1)" BT fundamental_chemical_element NT H_I H_II deuterium molecular_hydrogen negative_H_ion tritium RT 21-cm_line hydrogen_burning hydrogen_deficient_star hydrogen_spectrum HN "FVH: new (2007-OCT-25)" ## hydrogen_line hydrogen_line D "hydrogen line" N "see hydrogen spectrum" ## hydrogen_spectrum hydrogen_spectrum D "hydrogen spectrum" BT spectrum NT Balmer_continuum Balmer_series Brackett_series Lyman_continuum Lyman_series Paschen_series Pfund_series RT hydrogen ## hydrostatic_equilibrium hydrostatic_equilibrium D "hydrostatic equilibrium" RT stellar_structure ## hydroxyl_radical hydroxyl_radical ALT "OH" "OH radical" D "hydroxyl radical" BT interstellar_molecule ion radical RT OH_absorption OH_cloud OH_emission OH_IR_star OH_line OH_maser OH_source ## hyperbolic_orbit hyperbolic_orbit D "hyperbolic orbit" BT orbit RT circular_orbit elliptical_orbit parabolic_orbit ## hyperfine_line hyperfine_line D "hyperfine line" BT spectral_line RT spectrum ## hypergalaxy hypergalaxy D "hypergalaxy" BT galaxy ## hypergiant hypergiant D "hypergiant star" BT star RT supergiant ## hypernova hypernova D "hypernova" BT supernova RT gamma-ray_burst stellar_black_hole HN "FVH: new (2007-OCT-5)" ## hypothetical_planet hypothetical_planet D "hypothetical planet" BT planet ## HZ_Herculis_star HZ_Herculis_star D "HZ Herculis star" BT X-ray_pulsar low-mass_star neutron_star RT X-ray_binary_star X-ray_burst ## identification identification D "identification" N "e.g. catalog number, etc ## I_galaxy I_galaxy D "irregular galaxy (Yerkes classification scheme)" BT irregular_galaxy RT Yerkes_classification HN "FVH: new (2007-OCT-12)" ## illumination illumination D "illumination" RT albedo brightness intensity lunar_phase radiation N "of solar system body" ## image_processing image_processing D "image processing" RT clean_method flat_field image_reconstruction two-dimensional_detector ## image_reconstruction image_reconstruction D "image reconstruction" RT clean_method image_processing ## image image D "image" NT digital_image photograph RT Hartmann_test halation photography vision ## image_tube image_tube ALT "image converters" "image intensifier" "light amplifier" "photoelectric image tube" D "image tube" BT multi-channel_detector photoelectric_instrument photoelectronic_device two-dimensional_detector RT amplifier electrode electronic_camera microchannel_plate phosphorescence phosphorescent_scintillation photocathode quantum_efficiency scintillation_counter ## imaging_instrument imaging_instrument D "imaging instrument" BT instrument N "combine with other terms" ## I_magnitude I_magnitude D "I magnitude" BT apparent_magnitude RT Bessel_photometry Johnson_photometry Kron-Cousins_photometry infrared_photometry near_infrared_radiation ## impact_crater impact_crater D "impact crater" BT crater RT meteorite ## impersonal_astrolabe impersonal_astrolabe D "impersonal astrolabe" BT astrolabe ## inclination inclination D "inclination" BT orbital_element RT binary_star node ## indium indium ALT "In" D "indium (atomic number 49)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## indochinite indochinite D "indochinite" BT tektite ## inertial_coordinate_system inertial_coordinate_system D "inertial coordinate system" BT coordinate_system RT inertial_reference_frame relativity ## inertial_reference_frame inertial_reference_frame D "inertial reference frame" RT inertial_coordinate_system relativity ## inflationary_universe inflationary_universe D "inflationary universe" BT cosmology ## infrared_astronomy infrared_astronomy D "infrared astronomy" BT astronomy RT infrared_radiation infrared_telescope satellite-borne_instrument ## infrared_detector infrared_detector D "infrared detector" BT detector RT photometer ## infrared_emission infrared_emission D "infrared emission" BT emission_spectrum RT thermal_emission ## infrared_galaxy infrared_galaxy D "infrared galaxy" BT galaxy infrared_source NT IRAS_galaxy ## infrared infrared D "infrared" RT infrared_radiation N "combine with other terms" ## infrared_observatory infrared_observatory D "infrared observatory" BT observatory NT IRAS_satellite RT airplane-borne_instrument infrared_source rocket-borne_instrument space_observatory N "see observatory for more rts" ## infrared_photometry infrared_photometry D "infrared photometry" BT broad_band_photometry medium_band_photometry photometry RT H_magnitude I_magnitude J_magnitude K_magnitude L_magnitude M_magnitude N_magnitude O_magnitude P_magnitude Q_magnitude far_infrared_radiation near_infrared_radiation ## infrared_radiation infrared_radiation D "infrared radiation" BT electromagnetic_radiation radiation NT Brackett_series Pfund_series Phillips_band far_infrared_radiation near_infrared_radiation RT IRAS_satellite greenhouse_effect infrared infrared_astronomy remote_sensing terrestrial_radiation thermal_radiation ## infrared_source infrared_source D "infrared source" BT source NT FU_Orionis_star Herbig-Haro_object OH_IR_star cocoon_star extreme_carbon_star flare_star infrared_galaxy RT infrared_observatory star_formation ## infrared_telescope infrared_telescope D "infrared telescope" BT telescope RT infrared_astronomy ## infrared_transmission_window infrared_transmission_window D "infrared transmission window through the atmosphere" BT atmospheric_window RT optical_transmission_window radio_transmission_window CN "FVH: renamed to avoid confusion with optics (2007-NOV-2)" N "low absorption in atmosphere" ## inhomogenity inhomogenity D "inhomogenity" N "combine with other terms" ## initial_mass_function initial_mass_function ALT "IMF" D "initial mass function" RT mass mass-ratio star_cluster stellar_evolution ## inner_core inner_core D "inner core" RT helium_burning hydrogen_burning stellar_evolution stellar_interior N "central region of star" ## inner_planet inner_planet ALT "terrestrial planet" D "inner planet" BT planet RT outer_planet ## instability instability D "instability" NT Rayleigh-Taylor_instability N "combine with other terms" ## instability_strip instability_strip D "instability strip" RT Cepheid Hertzsprung-Russell_diagram giant_branch stellar_evolution ## instrumental_profile instrumental_profile D "instrumental profile" BT line_profile RT equivalent_width line_broadening line_width spectral_line ## instrument instrument ALT "astronomical instrument" "instrumentation" D "instrument" NT airplane-borne_instrument amplifier armillary_sphere astrolabe astrometric_instrument auxiliary_instrument blink_comparator bolometer coronagraph detector guide_system imaging_instrument interferometer magnetograph magnetoheliograph quadrant sextant spectrograph stroboscope telescope_instrument RT calibration electronic_equipment frequency_standard metrology peripheral support_system N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## integral_field_spectrograph integral_field_spectrograph D "integral field spectrograph" BT spectrograph RT multi-fiber_spectrograph multi-slit_spectrograph three-dimensional_spectrum HN "FVH: new (2007-SEP-21)" ## integrated_magnitude integrated_magnitude ALT "total magnitude" D "integrated magnitude" BT magnitude RT galaxy star_cluster ## integration_time integration_time D "integration time" RT brightness noise sensitivity signal-to-noise_ratio ## intensity intensity ALT "specific intensity" D "intensity" NT apparent_intensity RT brightness illumination luminosity magnitude N "combine with other terms" ## intensity_interferometer intensity_interferometer D "intensity interferometer" BT interferometer optical_interferometer RT Michelson_interferometer ## interacting_binary_star interacting_binary_star D "interacting binary star" BT binary_star NT X-ray_binary_star cataclysmic_variable_star RT Roche_lobe X-ray_bright_point eclipsing_binary_star eruptive_binary_star tidal_friction tidal_interaction ## interacting_galaxy interacting_galaxy D "interacting galaxy" BT galaxy peculiar_galaxy RT galaxy_encounter galaxy_merger tail tidal_distortion tidal_friction tidal_interaction ## interaction interaction D "interaction" NT electromagnetic_interaction gravitational_interaction strong_interaction weak_interaction RT equation_of_state nuclear_physics ## intercloud_gas intercloud_gas D "intercloud gas" BT intercloud_matter ## intercloud_matter intercloud_matter D "intercloud matter" BT interstellar_matter NT intercloud_gas ## interference_filter interference_filter D "interference filter" BT filter optical_component optical_filter RT interference_wave optical_film photometry ultraviolet_filter ## interference_fringe interference_fringe ALT "fringe patterns" "fringe" D "interference fringe" RT interference_wave interferometer interferometry optical_interferometry visibility_function ## interference_noise interference_noise D "interference [noise]" BT noise ## interference_spectrosocopy interference_spectrosocopy D "interference spectrosocopy" BT spectroscopy RT interference_wave ## interference_wave interference_wave D "interference [wave]" NT light_interference RT diffraction interference_filter interference_fringe interference_spectrosocopy interferometry optical_interferometry radio_interferometry shadow_band wave_motion ## interferometer interferometer D "interferometer" BT instrument NT Fabry-Perot_interferometer intensity_interferometer long_baseline_interferometer optical_interferometer phase_switching_interferometer radio_interferometer very_long_baseline_interferometer RT antenna array heterodyne interference_fringe radio_telescope telescope_array N "see also under interferometry" ## interferometric_correlation interferometric_correlation D "interferometric correlation" BT correlation RT cross-correlation interferometry receiver CN "FVH: changed from correlation to avoid mixup with generic term (2007-OCT-26)" N "combine with other terms" ## interferometry interferometry D "interferometry" BT astronomical_technique observing_technique NT long_baseline_interferometry optical_interferometry radio_interferometry speckle_interferometry very_long_baseline_interferometry RT angular_diameter aperture_synthesis correlation interference_fringe interference_wave interferometric_correlation radio_astrometry resolution visibility_function N "see also under interferometer" ## intergalactic_absorption intergalactic_absorption D "intergalactic absorption" BT absorption RT Lyman_alpha_forest absorption_coefficient intergalactic_matter intergalactic_space interstellar_absorption reddening ## intergalactic_cloud intergalactic_cloud D "intergalactic cloud" BT intergalactic_matter RT intergalactic_gas ## intergalactic_gas intergalactic_gas D "intergalactic gas" BT intergalactic_matter RT intergalactic_cloud ## intergalactic_matter intergalactic_matter D "intergalactic matter" NT Dark_Matter dust intergalactic_cloud intergalactic_gas RT cosmic_string galaxy_cluster intergalactic_absorption intergalactic_space interplanetary_matter interstellar_matter intracluster_matter ## intergalactic_space intergalactic_space D "intergalactic space" RT galaxy_void intergalactic_absorption intergalactic_matter ## interior interior D "interior" RT planet N "combine with other terms" ## intermediate_population_star intermediate_population_star D "intermediate population star" BT star RT population_II_star stellar_population ## intermediate_type_star intermediate_type_star D "intermediate type star" NT F_star G_star ## internal_motion internal_motion D "internal motion" BT motion N "combine with other terms" ## interplanetary_dust interplanetary_dust D "interplanetary dust" BT dust interplanetary_matter NT meteoroid RT grain interplanetary_gas ## interplanetary_gas interplanetary_gas D "interplanetary gas" BT interplanetary_matter RT interplanetary_dust interplanetary_grain solar_wind ## interplanetary_grain interplanetary_grain D "interplanetary grain" BT grain interplanetary_matter NT meteoroid RT adsorption graphite interplanetary_gas ## interplanetary_magnetic_field interplanetary_magnetic_field D "interplanetary magnetic field" BT magnetic_field ## interplanetary_matter interplanetary_matter ALT "interplanetary medium" D "interplanetary matter" NT interplanetary_dust interplanetary_gas interplanetary_grain meteoroid solar_wind RT asteroid circumstellar_matter comet gegenschein heliosphere intergalactic_matter interplanetary_scintillation interstellar_matter meteorite micrometeorite zodiacal_dust zodiacal_light ## interplanetary_scintillation interplanetary_scintillation D "interplanetary scintillation" BT scintillation RT interplanetary_matter interstellar_scintillation ionospheric_scintillation radio_source ## interstellar_absorption interstellar_absorption ALT "interstellar extinction" D "interstellar absorption" BT absorption NT OH_absorption RT Galactic_window Rayleigh_scattering Wolf_diagram absorption_coefficient intergalactic_absorption interstellar_dust interstellar_gas interstellar_reddening light_absorption reddened_star reddening window ## interstellar_bubble interstellar_bubble D "interstellar bubble" BT bubble N "combine with other terms" ## interstellar_communication interstellar_communication D "interstellar communication" RT extraterrestrial_life space_exploration ## interstellar_dust interstellar_dust D "interstellar dust" BT dust interstellar_matter RT adsorption dust_cloud grain graphite interstellar_absorption interstellar_gas reddening ## interstellar_gas interstellar_gas D "interstellar gas" BT interstellar_matter RT absorption heliosphere interstellar_absorption interstellar_dust interstellar_wind reddening ## interstellar_magnetic_field interstellar_magnetic_field D "interstellar magnetic field" BT magnetic_field RT spiral_arm ## interstellar_matter interstellar_matter ALT "interstellar medium" D "interstellar matter" NT Bok_globule C_II_region Dark_Matter H_I_region H_II_region OH_cloud cometary_globule dark_cloud dark_nebula dense_cloud dust dust_cloud dust_grain dust_nebula globule grain intercloud_matter interstellar_dust interstellar_gas interstellar_molecule molecular_cloud nebula nebular_filament reflection_nebula RT SiO_maser Stromgren_sphere circumstellar_matter cosmic_string galaxy_structure intergalactic_matter interplanetary_matter interstellar_reddening interstellar_scintillation maser radio_absorption radio_transmission_window selective_absorption spiral_arm torus ## interstellar_molecule interstellar_molecule D "interstellar molecule" BT interstellar_matter molecule NT CS ammonia carbon_compound hydrated_carbon hydroxyl_radical methane molecular_hydrogen water RT cosmochemistry giant_molecular_cloud molecular_cloud organic_molecule N "not a complete list of nts" ## interstellar_reddening interstellar_reddening D "interstellar reddening" BT reddening RT color_excess gas_to_dust_ratio interstellar_absorption interstellar_matter light_absorption light_scattering reddened_star reddening_law selective_absorption ## interstellar_scintillation interstellar_scintillation D "interstellar scintillation" BT scintillation RT interplanetary_scintillation interstellar_matter ionospheric_scintillation radio_source ## interstellar_wind interstellar_wind D "interstellar wind" RT interstellar_gas solar_wind stellar_wind ## intracluster_matter intracluster_matter D "intracluster matter" RT Sunyaev-Zeldovich_effect galaxy_cluster intergalactic_matter ## intrinsic_color intrinsic_color D "intrinsic color" RT color_index photometry reddening ## intrinsic_variable_star intrinsic_variable_star ALT "unstable star" D "intrinsic variable star" BT variable_star NT Herbig-Haro_object magnetic_variable_star pulsating_variable_star spectrum_variable_star ## inverse_Compton_effect inverse_Compton_effect D "inverse Compton effect" RT cosmic_ray electron high-energy_astrophysics photon ## inverse_Compton_scattering inverse_Compton_scattering D "inverse Compton scattering" RT Compton_scattering electron photon ## inverse_maser inverse_maser D "inverse maser" RT maser ## iodine_cell iodine_cell D "iodine cell" BT optical_filter radial_velocity HN "FVH: new (2007-OCT-25)" ## iodine iodine ALT "I" D "iodine (atomic number 53)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## ion_composition ion_composition D "ion composition" RT ion ## ion_density ion_density D "ion density" RT ionization ion ## ionization_equilibrium ionization_equilibrium ALT "ionisation equilibrium UK" D "ionization equilibrium" RT ionization ## ionization ionization ALT "ionisation UK" D "ionization" NT photoionization RT Schwarzschild_metric Stromgren_sphere corona ion_density ionization_equilibrium shock ## ionized_gas ionized_gas D "ionized gas" BT gas NT H_II RT Stromgren_sphere collisional_excitation ion plasma ## ionizing_shock_wave ionizing_shock_wave D "ionizing shock wave" BT shock_wave ## ionosphere ionosphere D "ionosphere" RT D_layer E_layer Earth_atmosphere F_layer exosphere ionospheric_scintillation mesopause radio_absorption thermosphere upper_atmosphere ## ionospheric_scintillation ionospheric_scintillation D "ionospheric scintillation" BT scintillation RT interplanetary_scintillation interstellar_scintillation ionosphere radio_source ## ion_plasma_wave ion_plasma_wave D "ion plasma wave" RT ion plasma_wave ## ion ion ALT "charged particle" D "ion" BT composite_particle particle NT hydroxyl_radical RT Paul_trap Saha_equation collisional_excitation collisional_plasma ion_composition ion_density ion_plasma_wave ionized_gas plasma_cloud plasma_jet plasma polarization_charge_separation radical thermionic_emission ## ion_temperature ion_temperature D "ion temperature" BT temperature ## IRAS_galaxy IRAS_galaxy D "IRAS galaxy" BT infrared_galaxy RT IRAS_satellite ## IRAS_satellite IRAS_satellite ALT "IRAS" D "InfraRed Astronomical Satellite" BT infrared_observatory space_observatory RT IRAS_galaxy infrared_radiation HN "FVH: new, because of IRAS_galaxy (2007-NOV-1)" ## iridium iridium ALT "Ir" D "iridium (atomic number 77)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## iron iron ALT "Fe" D "iron (atomic number 26)" BT fundamental_chemical_element RT iron_meteorite HN "FVH: new (2007-OCT-25)" ## iron_meteorite iron_meteorite D "iron meteorite" BT meteorite RT iron ## irradiance irradiance D "irradiance" RT radiation ## irregular_galaxy irregular_galaxy D "irregular galaxy" BT galaxy NT I_galaxy Magellanic_cloud ## irregular_variable_star irregular_variable_star D "irregular variable star" BT late-type_giant pulsating_variable_star variable_star NT Mira_variable_star R_Coronae_Borealis_star RV_Tauri_star RW_Aurigae_star T_Tauri_star UU_Herculis_star dwarf_Cepheid gamma_Cassiopeiae_star soft_gamma-ray_repeater RT T_association late-type_supergiant semi-regular_variable_star supergiant ## isophotal_diameter isophotal_diameter D "isophotal diameter" BT angular_diameter diameter RT galaxy isophot luminosity_distribution surface_photometry HN "ES: new (2007-OCT-11)" ## isophot isophot D "isophot" RT contour_map isophotal_diameter luminosity_distribution surface_photometry ## isothermal_sphere isothermal_sphere D "isothermal mass-profile" BT mass_distribution RT Burkert_profile Navarro-Frenk-White_profile exponential_profile HN "FVH: new (2007-OCT-5)" ## isotope isotope D "isotope" BT chemical_element RT deuterium tritium ## isotopic_abundance isotopic_abundance D "isotopic abundance" BT abundance RT isotopic_composition ## isotopic_composition isotopic_composition D "isotopic composition" RT isotopic_abundance ## isotropy isotropy D "isotropy" RT anisotropy optical_property ## Jansky Jansky D "Jansky" RT radio_radiation N "radio flux density unit" ## Jeans_length Jeans_length D "Jeans length" RT Jeans_mass gravity star_formation ## Jeans_mass Jeans_mass D "Jeans mass" RT Jeans_length ## jet jet ALT "astrophysical jet" D "jet" BT mass-loss NT plasma_jet radio_jet RT comet hydrodynamics radio_source ## J_magnitude J_magnitude D "J magnitude" BT apparent_magnitude RT infrared_photometry near_infrared_radiation ## Johnson_noise Johnson_noise D "Johnson noise" RT thermal_radiation ## Johnson_photometry Johnson_photometry ALT "Johnson-Morgan filter system" "UBV photometry" "UBVRI photometry" "UBVRIJKL photometry" "three-color photometry" D "Johnson photometry" BT broad_band_photometry photometric_system RT B_magnitude Bessel_photometry BV_photometry Cape_photometry Cape_RI_photometry I_magnitude Kron-Cousins_photometry R_magnitude U_magnitude V_magnitude e_region f_region two-color_photometry ## Jovian_planet Jovian_planet D "Jovian planet" BT outer_planet NT Jupiter Neptune Saturn Uranus ## Julian_calendar Julian_calendar D "Julian calendar" BT calendar RT Gregorian_calendar Julian_Date Julian_epoch ## Julian_Date Julian_Date ALT "J.D." "JD" D "Julian Date" NT heliocentric_Julian_Date RT Julian_calendar epoch time ## Julian_epoch Julian_epoch D "Julian epoch" BT epoch standard_epoch RT Besselian_epoch Julian_calendar time ## jump_condition jump_condition D "jump condition" RT shock_wave ## Jupiter Jupiter D "Jupiter" BT Jovian_planet planet RT Solar_System HN "FVH: new (2007-SEP-24)" ## kappa_mechanism kappa_mechanism D "kappa mechanism" RT Cepheid He_II_ionization_zone ZZ_Ceti_star delta_Scuti_star pulsating_variable_star ## Kapteyn_selected_area Kapteyn_selected_area D "Kapteyn selected area" NT e_region f_region RT Cape_photometry Stromgren_photometry ## K_corona K_corona ALT "K-corona" D "K corona" BT corona RT solar_corona ## k_correction k_correction ALT "k-term" D "k-correction" RT redshift ## K_dwarf K_dwarf D "K dwarf star" BT K_star dwarf late-type_dwarf RT K_subdwarf ## Kellner_eyepiece Kellner_eyepiece D "Kellner eyepiece" BT eyepiece ## Kelvin Kelvin D "Kelvin" BT absolute_temperature_scale RT celsius_temperature_scale temperature_scale N "ES: moved absolute_temperature_scale from RT to BT (2007-OCT-8)" "absolute temperature scale units" ## Kelvin_timescale Kelvin_timescale D "Kelvin timescale" RT Helmholtz-Kelvin_contraction ## Keplerian_orbit Keplerian_orbit D "Keplerian orbit" BT orbit RT celestial_mechanics ## Kerr_black_hole Kerr_black_hole D "Kerr black hole" BT black_hole RT stellar_evolution ## K_giant K_giant D "K giant star" BT K_star late-type_giant RT K_subgiant ## kinematic_parallax kinematic_parallax D "kinematic parallax" BT parallax RT dynamical_parallax moving_cluster_parallax ## kinematics kinematics D "kinematics" NT acceleration RT Galactic_rotation Galactic_structure angular_momentum galaxy_rotation_curve galaxy_structure proper_motion radial_velocity velocity ## kinetic_energy kinetic_energy D "kinetic energy" BT energy RT potential_energy ## Kirkwood_gap Kirkwood_gap D "Kirkwood gap" BT resonance_gap RT asteroid ## K_line K_line D "K line" BT Fraunhofer_line H_and_K_line calcium_line RT H_line Wilson-Bappu_effect ## K_magnitude K_magnitude D "K magnitude" BT apparent_magnitude RT infrared_photometry near_infrared_radiation ## Kramers_opacity Kramers_opacity D "Kramers opacity" BT opacity RT Rosseland_opacity ## Kreutz_sungrazer Kreutz_sungrazer ALT "sungrazer" D "Kreutz sungrazer" BT comet RT Solar_System ## Kron-Cousins_photometry Kron-Cousins_photometry ALT "Kron Cousins photometry" "Kron-Cousins R,I photometry" D "Kron-Cousins photometry" BT broad_band_photometry photometric_system RT I_magnitude Johnson_photometry R_magnitude HN "FVH: new (2007-SEP-21)" ## Kruskal_diagram Kruskal_diagram D "Kruskal diagram" RT black_hole ## krypton krypton ALT "Kr" D "krypton (atomic number 36)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## K_star K_star D "K star" BT late-type_star NT K_dwarf K_giant K_subdwarf K_subgiant K_supergiant RT spectral_type ## K_subdwarf K_subdwarf D "K subdwarf star" BT K_star subdwarf RT K_dwarf ## K_subgiant K_subgiant D "K subgiant star" BT K_star subgiant RT K_giant ## K_supergiant K_supergiant D "K supergiant star" BT K_star late-type_supergiant supergiant ## Lagrangian_point Lagrangian_point ALT "libration point" D "Lagrangian point" RT celestial_mechanics gravitation gravitational_field ## lambda_eridani_star lambda_eridani_star D "lambda Eridani star" BT Be_star pulsating_variable_star ## lamp lamp D "lamp" NT comparison_lamp flat_field_lamp RT calibration electromagnetic_radiation ## lanthanum lanthanum ALT "La" D "lanthanum (atomic number 57)" BT fundamental_chemical_element rare_earth HN "FVH: new (2007-OCT-25)" ## Large_Magellanic_Cloud Large_Magellanic_Cloud ALT "LMC" D "Large Magellanic Cloud" BT Magellanic_cloud RT Small_Magellanic_Cloud ## large_scale_structure large_scale_structure D "large scale structure" RT cosmic_string cosmology universe CN "FVH: added RT COSMOLOGY (2007-SEP-21)" ## laser_ranging laser_ranging D "laser ranging" NT lunar_laser_ranging satellite_laser_ranging RT optical_radar ## laser laser D "laser" RT coherence electron_pumping light_coherence lunar_laser_ranging maser optical_radar population_inversion satellite_laser_ranging stimulated_emission ## late-type_dwarf late-type_dwarf ALT "cool dwarf star" "late type dwarf star" D "late-type dwarf star" BT dwarf late-type_star low-luminosity_star NT K_dwarf L_dwarf M_dwarf brown_dwarf red_dwarf_flare_star ## late-type_galaxy late-type_galaxy ALT "late type galaxy" D "late-type galaxy" BT galaxy RT spiral_galaxy ## late-type_giant late-type_giant ALT "cool giant star" "late type giant star" D "late-type giant star" BT giant late-type_star NT K_giant M_giant Mira_variable_star carbon_star heavy_metal_star irregular_variable_star semi-regular_variable_star RT asymptotic_giant_branch funneling post-asymptotic_giant_branch red_giant_tip ## late-type_star late-type_star ALT "cool star" "late type star" D "late-type star" BT star NT K_star M_star N_star R_star S_star late-type_dwarf late-type_giant late-type_subdwarf late-type_supergiant RT Wilson-Bappu_effect molecular_band molecular_line molecular_spectrum ## late-type_subdwarf late-type_subdwarf ALT "cool subdwarf star" D "late-type subdwarf" BT late-type_star low-luminosity_star subdwarf NT L_subdwarf brown_dwarf ## late-type_supergiant late-type_supergiant ALT "cool supergiant star" D "late-type supergiant star" BT late-type_star supergiant NT K_supergiant M_supergiant RV_Tauri_star RT irregular_variable_star long_period_variable_star ## late-type_variable_star late-type_variable_star D "late-type variable star" NT Me_variable_star RT Me_star ## latitude_determination latitude_determination D "latitude determination" NT latitude_variation RT Chandler_wobble astrometry N "on Earth surface" ## latitude latitude D "latitude" NT Declination ecliptic_latitude Galactic_latitude supergalactic_latitude N "on celestial sphere" ## latitude_variation latitude_variation D "latitude variation" BT latitude_determination RT Chandler_wobble polar_motion N "on Earth surface" ## lawrencium lawrencium ALT "Lr" D "lawrencium (atomic number 103)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Lb_variable_star Lb_variable_star D "Lb variable star" BT giant ## Lc_variable_star Lc_variable_star D "Lc variable star" RT supergiant ## L_dwarf L_dwarf D "L dwarf" BT brown_dwarf late-type_dwarf RT L_subdwarf spectral_type titanium_oxide HN "FVH: new (2007-OCT-2)" ## lead lead ALT "Pb" D "lead (atomic number 82)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Lemaitre_universe Lemaitre_universe D "Lemaitre universe" BT cosmology RT Big_Bang_theory ## lens_antenna lens_antenna ALT "lens antennas" D "lens antenna" BT antenna ## lens_design lens_design D "lens design" RT lens ## lens lens D "lens" BT optical_component NT camera_lens corrector_plate field_corrector primary_lens RT antireflection_coating catadioptric_system coating collimator dioptric_system eyepiece figuring glass lens_design optical_aberration optical_instrument optical_material optical_surface polishing refraction refractive_index ## lenticular_galaxy lenticular_galaxy ALT "S0 galaxy" D "lenticular galaxy" BT disk_galaxy galaxy RT ansa ## lepton lepton D "lepton" BT elementary_particle particle NT electron muon neutrino positron RT boson quark ## L_galaxy L_galaxy D "low surface-brightness galaxy (Yerkes classification scheme)" BT galaxy RT Yerkes_classification surface_brightness ## libration libration ALT "physical libration" D "libration" RT Moon ## life life D "life" NT extraterrestrial_life RT anthropic_principle origin ## light_absorption light_absorption D "light absorption" BT absorption RT atmospheric_extinction electromagnetic_radiation interstellar_absorption interstellar_reddening light_scattering visible_radiation ## light_coherence light_coherence D "light coherence" BT coherence RT laser ## light_cone light_cone D "light cone" NT future_light_cone past_light_cone RT velocity_of_light ## light_curve light_curve D "light curve" BT photometric_element RT magnitude maximum minimum period phase_shift phase_wave variable_star velocity_curve ## light_emission light_emission D "light emission" NT photoluminescence RT aurora chemiluminescence continuous_spectrum emission_spectrum luminescence ## light_interference light_interference D "light interference" BT interference_wave RT electromagnetic_radiation optical_film optical_filter optical_interferometry visible_radiation ## light_polarization light_polarization ALT "polarization wave" D "light polarization" NT X-ray_polarization circular_polarization plane_polarization RT Faraday_effect electromagnetic_radiation optical_property polarimetry polarized_light polarized_radiation radiation_scattering stokes_parameter ## light_pollution light_pollution D "light pollution" BT pollution RT air_pollution site_protection ## light_scattering light_scattering D "light scattering" BT radiation_scattering scattering NT Compton_scattering Rayleigh_scattering Thomson_scattering RT Raman_spectrum afterglow atmospheric_extinction brillouin_spectrum electromagnetic_radiation halo interstellar_reddening light_absorption luminescence visible_radiation zodiacal_light ## light_year light_year D "light year" RT distance parsec velocity_of_light year ## limb_brightening limb_brightening D "limb brightening" RT atmosphere limb_darkening stellar_atmosphere temperature ## limb_darkening limb_darkening D "limb darkening" RT atmosphere limb_brightening solar_atmosphere stellar_atmosphere temperature ## limiting_magnitude limiting_magnitude D "limiting magnitude" RT detector precision sensitivity signal_detection signal-to-noise_ratio ## linearity_calibration linearity_calibration D "linearity calibration" BT calibration HN "FVH: new (2007-OCT-3)" ## line_blanketing line_blanketing D "line blanketing" RT metal_line spectral_line ultraviolet_radiation ## line_blending line_blending D "line blending" RT spectral_line spectral_resolution ## line_blocking line_blocking D "line blocking" N "see under line blanketing" ## line_broadening line_broadening ALT "spectral line broadening" D "line broadening" NT Doppler_broadening Stark_broadening collision_broadening natural_line_broadening pressure_broadening RT Zeeman_splitting convection equivalent_width instrumental_profile line_formation line_width natural_line_width spectral_line stellar_atmosphere turbulence_star_atmosphere ## line_formation line_formation ALT "spectral line formation" D "line formation" RT absorption_line damping_constant emission_line g_value gf_value line_broadening oscillator_strength solar_atmosphere spectral_line stellar_atmosphere transition_probability ## line_identification line_identification D "line identification" RT absorption_line emission_line spectral_line ## line_intensitite line_intensitite D "line intensitite" RT emission_line spectral_line ## line_profile line_profile D "line profile" BT profile NT P_Cygni_line_profile instrumental_profile RT absorption_line emission_line residual_intensity spectral_line ## line_ratio line_ratio D "line ratio" RT absorption_line emission_line spectral_line ## liner_galaxy liner_galaxy D "liner galaxy" BT emission_line_galaxy RT Seyfert_galaxy quasar HN "FVH: new (2007-SEP-21)" ## line_shift line_shift ALT "spectral line shift" D "line shift" NT blueshift redshift RT Doppler_effect Zeeman_splitting radial_velocity ## line_of_sight line_of_sight D "line-of-sight" BT location RT location_behind location_between location_in_front HN "FVH: new (2007-SEP-21)" ## line_spectrum line_spectrum D "line spectrum" NT absorption_spectrum emission_spectrum RT Voigt_profile pressure_broadening ultraviolet_line ## line_width line_width ALT "spectral line width" D "line width" NT equivalent_width natural_line_width RT Doppler_broadening Milne_Eddington_approximation Tully-Fisher_relation g_value gf_value instrumental_profile line_broadening oscillator_strength spectral_type stellar_atmosphere surface_gravity transition_probability ## lithium lithium ALT "Li" D "lithium (atomic number 3)" BT fundamental_chemical_element RT lithium-poor_star lithium_star HN "FVH: new (2007-OCT-25)" ## lithium-poor_star lithium-poor_star ALT "lithium poor star" D "lithium-poor star" BT metal-poor_star RT lithium ## lithium_star lithium_star ALT "Li star" "lithium rich star" "lithium-rich star" D "lithium star" BT star RT giant lithium ## lithosphere lithosphere D "lithosphere" RT mantle planet ## L_magnitude L_magnitude D "L magnitude" BT apparent_magnitude RT infrared_photometry near_infrared_radiation ## lobe lobe D "lobe" BT radio_structure RT radio_source N "radio source feature" ## Local_Group Local_Group D "Local Group of galaxies" BT galaxy_group nearby_galaxy NT Magellanic_cloud Milky_Way_galaxy RT bright_galaxy ## Local_Standard_of_Rest Local_Standard_of_Rest ALT "LSR" "L.S.R." D "Local Standard of Rest" RT Sun orbit peculiar_motion peculiar_velocity proper_motion stellar_motion ## Local_Supercluster Local_Supercluster D "Local Supercluster of galaxies" BT galaxy_cluster RT Great_Attractor galaxy ## local_thermodynamic_equilibrium local_thermodynamic_equilibrium ALT "LTE" D "local thermodynamic equilibrium" BT thermodynamic_equilibrium RT non-LTE_transfer thermal_equilibrium thermal_instability thermal_stability thermodynamics ## location_behind location_behind D "location behind something else" BT location RT line_of_sight location_between location_in_front HN "FVH: new (2007-SEP-21)" ## location_between location_between D "location between" BT location RT line_of_sight location_behind location_in_front HN "FVH: new (2007-SEP-21)" ## location_in_front location_in_front D "location in front of something else" BT location RT line_of_sight location_behind location_between HN "FVH: new (2007-SEP-21)" ## location location D "having to do with cosmic location" NT line_of_sight location_behind location_between location_in_front HN "FVH: new (2007-SEP-21)" ## log_g_value log_g_value D "log(g) value" BT g_value RT gf_value HN "ES: new (2007-OCT-8)" "logarithm reference needed!" ## long_baseline_interferometer long_baseline_interferometer D "long baseline interferometer" BT interferometer radio_interferometer RT optical_interferometer very_long_baseline_interferometer ## long_baseline_interferometry long_baseline_interferometry D "long baseline interferometry" BT interferometry radio_interferometry RT optical_interferometry radio_astrometry very_long_baseline_interferometry ## longitude longitude D "longitude" NT Galactic_longitude ecliptic_longitude Right_Ascension supergalactic_longitude N "on celestial sphere" ## long_period_comet long_period_comet D "long period comet" BT comet ## long_period_variable_star long_period_variable_star D "long period variable star" BT pulsating_variable_star NT Mira_variable_star RV_Tauri_star S_Vulpeculae_star WZ_Sagittae_star RT late-type_supergiant ## long_slit long_slit D "long slit" BT spectrograph_slit HN "FVH: new (2007-OCT-3)" ## long_slit_spectrum long_slit_spectrum D "long slit spectrum" RT spectrograph_slit three-dimensional_spectrum two-dimensional_spectrum CN "FVH: added RT SPECTROGRAPH_SLITS (2007-SEP-21)" ## loop loop D "loop" N "combine with other terms" ## low-luminosity_star low-luminosity_star ALT "low luminosity star" D "low-luminosity star" BT star NT late-type_dwarf late-type_subdwarf RT dwarf low-mass_star ## low-mass_star low-mass_star ALT "low mass star" D "low-mass star" BT star NT HZ_Herculis_star black_dwarf RT T_dwarf brown_dwarf dwarf low-luminosity_star low-mass_X-ray_binary_star CN "FVH+ES: moved brown_dwarf to RT (2007-OCT-11)" ## low-mass_X-ray_binary_star low-mass_X-ray_binary_star ALT "LMXB" D "low-mass X-ray binary star" BT X-ray_binary_star RT accretion_disk cataclysmic_variable_star high-mass_X-ray_binary_star low-mass_star neutron_star ## low-state low-state D "photometric low state of variable object" RT high-state outburst variability variable_source HN "FVH: new (2007-OCT-8)" ## low-temperature_plasma low-temperature_plasma D "low temperature plasma" BT plasma ## L_subdwarf L_subdwarf D "L subdwarf" BT brown_dwarf late-type_subdwarf subdwarf RT L_dwarf HN "FVH: new (2007-OCT-9)" ## luminescence luminescence ALT "candoluminescence" D "luminescence" NT chemiluminescence thermoluminescence RT afterglow electromagnetic_radiation fluorescence light_emission light_scattering noctilucent_cloud visible_radiation ## luminosity_classification luminosity_classification D "luminosity classification" BT classification RT dwarf giant luminosity_class spectral_classification spectral_type subgiant surface_gravity ## luminosity_class luminosity_class D "luminosity class" BT MK_classification RT luminosity luminosity_classification spectral_type N "see: luminosity classification" ## luminosity-dispersion_relation luminosity-dispersion_relation D "luminosity-dispersion relation" BT correlation NT Faber-Jackson_relation fundamental_plane RT luminosity velocity_dispersion HN "FVH: new (2007-OCT-9)" ## luminosity_distribution luminosity_distribution D "luminosity distribution" RT brightness_temperature isophotal_diameter isophot ## luminosity_function luminosity_function D "luminosity function" RT galaxy galaxy_cluster star_cluster stellar_evolution ## luminosity luminosity D "luminosity" NT X-ray_luminosity ultraviolet_luminosity RT Hertzsprung-Russell_diagram MK_classification absolute_magnitude brightness flux flux_density intensity luminosity_class luminosity-dispersion_relation mass_to_light_ratio surface_gravity CN "FVH: removed UF absolute_intensity as unphysical misnomer (2007-SEP-24)" ## luminous_arc luminous_arc D "luminous arc produced by gravitational lensing" BT arc gravitationally_lensed_source RT galaxy_cluster gravitational_lensing quasar CN "FVH: changed UF arc to BT ARCS and QUASARS to CLUSTERS_OF_GALAXIES (2007-OCT-1)" "FVH: moved BT arc to RT arc and added BT gravitationally_lensed_source (2007-OCT-8)" ## luminous_blue_variable_star luminous_blue_variable_star D "luminous blue variable star" BT early-type_variable_star high-luminosity_star RT early-type_supergiant ## lunar_dome lunar_dome D "lunar dome" RT Moon surface_of_celestial_body ## lunar_eclipse lunar_eclipse D "lunar eclipse" BT eclipse RT Moon Saros_cycle Sun penumbra umbra ## lunar_laser_ranging lunar_laser_ranging D "lunar laser ranging" BT laser_ranging RT Moon laser optical_radar satellite_laser_ranging ## lunar lunar D "lunar" N "combine lunar or Moon with other terms; also see Moon" ## lunar_occultation lunar_occultation D "occultation by the Moon" BT occultation RT Moon HN "FVH: new (2007-OCT-8)" ## lunar_phase lunar_phase ALT "phase Moon" D "phase of the Moon" RT Saros_cycle illumination metonic_cycle phase_angle phase_defect phase_effect terminator_line ## lunar_theory lunar_theory D "lunar theory" RT Earth-Moon_system Moon celestial_mechanics ## lutetium lutetium ALT "Lu" D "lutetium (atomic number 71)" BT fundamental_chemical_element rare_earth HN "FVH: new (2007-OCT-25)" ## Lyman_alpha Lyman_alpha D "Lyman alpha" BT Lyman_series resonance_line RT Lyman_alpha_forest ## Lyman_alpha_forest Lyman_alpha_forest D "Lyman alpha forest" RT Lyman_alpha absorption_line intergalactic_absorption quasar redshift ## Lyman_beta Lyman_beta D "Lyman beta" BT Lyman_series ## Lyman_continuum Lyman_continuum D "Lyman continuum" BT hydrogen_spectrum RT ultraviolet_radiation ## Lyman_series Lyman_series D "Lyman series" BT hydrogen_spectrum NT Lyman_alpha Lyman_beta RT Balmer_series Brackett_series Paschen_series Pfund_series ultraviolet_radiation ## macro_spicule macro_spicule D "macro spicule" BT spicule RT Sun chromosphere ## macroturbulence macroturbulence D "macroturbulence" BT turbulence_Earth_atmosphere turbulence_star_atmosphere RT atmosphere stellar_structure ## Magellanic_cloud Magellanic_cloud ALT "Clouds of Magellan" D "Magellanic cloud" BT galaxy irregular_galaxy Local_Group nearby_galaxy NT Large_Magellanic_Cloud Small_Magellanic_Cloud RT Magellanic_stream ## Magellanic_stream Magellanic_stream D "Magellanic stream" RT Magellanic_cloud ## magnesium magnesium ALT "Mg" D "magnesium (atomic number 12)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## magnetar magnetar D "magnetar" BT magnetic_star neutron_star NT soft_gamma-ray_repeater HN "ES: new (2007-OCT-8)" ## magnetic_anomaly magnetic_anomaly D "magnetic anomaly" BT anomaly RT gravity_anomaly magnetic_property ## magnetic_disturbances magnetic_disturbances D "magnetic disturbances" RT aurora magnetic_property ## magnetic_field magnetic_field D "magnetic field" NT emerging_flux geomagnetic_field interplanetary_magnetic_field interstellar_magnetic_field RT Paschen-Back_effect dynamo_theory force magnetic_monopole magnetic_pole magnetic_property magnetic_variable_star magnetohydrodynamics magnetosphere paleomagnetism sunspot ## magnetic_monopole magnetic_monopole D "magnetic monopole" RT magnetic_field magnetic_pole ## magnetic_pole magnetic_pole D "magnetic pole" RT aurora magnetic_field magnetic_monopole magnetic_storm magnetic_variable_star ## magnetic_property magnetic_property D "magnetic property" BT property RT magnetic_anomaly magnetic_disturbances magnetic_field magnetic_star ## magnetic_star magnetic_star ALT "cobalt star" D "magnetic star" BT peculiar_star NT Am_star Bp_star magnetar magnetic_variable_star manganese_star mercury_manganese_star RT Ap_star cobalt magnetic_property oblique_rotator spectrum_variable_star strontium_star ## magnetic_storm magnetic_storm D "magnetic storm" NT magnetospheric_substorm RT aurora magnetic_pole magnetosphere solar_activity sunspot ## magnetic_variable_star magnetic_variable_star D "magnetic variable star" BT intrinsic_variable_star magnetic_star NT Am_star SX_Arietis_star alpha2_Canum_Venaticorum_star RT Ap_star magnetic_field magnetic_pole ## magnetograph magnetograph D "magnetograph" BT instrument ## magnetoheliograph magnetoheliograph D "magnetoheliograph" BT instrument ## magnetohydrodynamics magnetohydrodynamics ALT "MHD" "hydromagnetics" D "magnetohydrodynamics" NT Alfven_wave RT cosmic_electrodynamics hydrodynamics magnetic_field plasma_physics plasma_wave synchrotron_radiation van_Allen_radiation_belt CN "FVH: moved mhd to ALT, ALFVEN_WAVES to NT (2007-SEP-24)" ## magneto-optical_effect magneto-optical_effect ALT "magneto optical effect" D "magneto-optical effect" NT Faraday_effect Zeeman_splitting polarization_charge_separation ## magnetosphere magnetosphere D "magnetosphere" RT Earth_atmosphere exosphere magnetic_field magnetic_storm magnetospheric_substorm upper_atmosphere ## magnetospheric_substorm magnetospheric_substorm D "magnetospheric substorm" BT magnetic_storm RT magnetosphere ## magnitude magnitude D "magnitude" NT absolute_magnitude apparent_magnitude integrated_magnitude RT Pogson_scale amplitude brightness intensity light_curve photometry N "also see under apparent magnitude" ## main_sequence main_sequence D "main sequence" RT Hertzsprung-Russell_diagram dwarf main_sequence_star turnoff_point zero-age_main_sequence ## main_sequence_star main_sequence_star D "main sequence star" BT star NT blue_straggler_star dwarf RT main_sequence mass-luminosity_relation N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## major_axis major_axis D "major axis" BT semimajor_axis RT axial_ratio minor_axis N "see terms under semimajor axis" ## Maksutov_telescope Maksutov_telescope D "Maksutov telescope" BT catadioptric_system reflecting_telescope RT Bouwers_telescope Schmidt_telescope wide-field_telescope ## manganese manganese ALT "Mn" D "manganese (atomic number 25)" BT fundamental_chemical_element RT manganese_star mercury_manganese_star HN "FVH: new (2007-OCT-25)" ## manganese_star manganese_star D "manganese star" BT Ap_star magnetic_star spectrum_variable_star RT manganese ## mantle mantle D "mantle" RT Earth Moon crust crustal_dynamics lithosphere planet ## map map D "map" NT X-ray_map contour_map RT atlas catalog finding_chart photogrammetry planet radar_mapping sky_survey star_atlas ## maria maria D "maria" RT Moon surface_of_celestial_body ## Markarian_galaxy Markarian_galaxy D "Markarian galaxy" BT emission_line_galaxy RT Seyfert_galaxy peculiar_galaxy ## Mars Mars D "Mars" BT planet RT Solar_System HN "FVH: new (2007-SEP-24)" ## mascon mascon D "mascon" RT Moon gravity_anomaly ## maser maser D "maser" NT OH_maser SiO_maser megamaser water_maser RT coherence electron_pumping interstellar_matter inverse_maser laser population_inversion radio_recombination_line radio_source stimulated_emission ## mass_density mass_density D "mass-density" BT density RT Omega_baryon Omega_mass Omega_parameter mass CN "FVH: added NT OMEGA_PARAMETER (2007-SEP-21)" ## mass_distribution mass_distribution D "mass distribution" NT Burkert_profile Navarro-Frenk-White_profile exponential_profile isothermal_sphere RT Dark_Matter disk_galaxy galaxy galaxy_cluster galaxy_rotation_curve galaxy_structure gravitational_lensing HN "FVH: new (2007-OCT-5)" ## mass_exchange mass_exchange ALT "exchange of mass" D "mass-exchange" RT cataclysmic_variable_star contact_binary_star eruptive_binary_star mass mass_flow mass-loss mass-transfer ## mass_flow mass_flow D "mass-flow" RT mass mass_exchange mass-loss mass-transfer ## mass_function mass_function D "mass-function" RT birth_rate mass mass-ratio spectroscopic_binary_star star_cluster star_count ## massive_galaxy massive_galaxy D "massive galaxy" BT galaxy NT cD_galaxy RT D_galaxy galaxy_cluster ## massive_object massive_object D "massive object" RT Seyfert_galaxy black_hole galactic_nucleus ## massive_star massive_star D "massive star" BT star RT mass-loss supermassive_star ## mass-loss mass-loss ALT "mass loss" "mass-ejection" D "mass-loss" NT bipolar_outflow coronal_mass_ejection jet stellar_wind RT FU_Orionis_star P_Cygni_line_profile Wolf-Rayet_star binary_star cataclysmic_variable_star circumstellar_disk circumstellar_envelope circumstellar_matter circumstellar_shell corona eruptive_binary_star mass_exchange mass_flow mass-transfer massive_star nova planetary_nebula stellar_evolution supernova ## mass-luminosity_relation mass-luminosity_relation ALT "mass luminosity relation" D "mass-luminosity relation" BT statistical_relation RT main_sequence_star ## mass mass D "mass" NT Chandrasekhar_mass Chandrasekhar-Schoenberg_limit RT gravitation initial_mass_function mass_density mass_exchange mass_flow mass_function mass_to_light_ratio momentum spectroscopic_binary_star surface_gravity ## mass-radius_relation mass-radius_relation ALT "mass radius relation" D "mass-radius relation" BT statistical_relation RT Chandrasekhar_mass Chandrasekhar-Schoenberg_limit degenerate_star ## mass-ratio mass-ratio ALT "mass ratio" D "mass-ratio" RT binary_star initial_mass_function mass_function ## mass_to_light_ratio mass_to_light_ratio D "mass-to-light ratio" RT galaxy luminosity mass missing_mass ## mass-transfer mass-transfer ALT "mass transfer" D "mass-transfer" RT accretion convection fluid_dynamics mass_exchange mass_flow mass-loss ## mathematical_analysis mathematical_analysis D "mathematical analysis" NT differential_equation RT catastrophe_theory N "combine with other terms" ## mathematical_model mathematical_model D "mathematical model" RT computer_model CN "FVH: changed COMPUTER_MODELS from U to RT (2007-SEP-21)" ## mathematics mathematics D "mathematics" BT scientific_field N "combine with other terms" ## matter matter D "matter" NT antimatter atom circumplanetary_matter circumstellar_matter degenerate_matter molecule ## Maunder_minimum Maunder_minimum D "Maunder minimum" RT solar_activity sunspot_cycle sunspot_number ## maximum maximum D "maximum" BT photometric_element RT light_curve minimum variable_star velocity_curve ## maximum_entropy_method maximum_entropy_method D "maximum entropy method" RT Fourier_analysis frequency_analysis spectroscopic_analysis ## M_dwarf M_dwarf D "M dwarf star" BT M_star dwarf late-type_dwarf ## mean_anomaly mean_anomaly D "mean anomaly" BT orbital_anomaly ## mean_equinox mean_equinox D "mean equinox" BT equinox RT planet ## mean_solar_time mean_solar_time D "mean solar time" BT time RT Universal_Time civil_time ephemeris_time equation_of_time ## measurement measurement D "measurement" RT determination measuring_instrument metrology quantization N "combine with other terms" ## measuring_instrument measuring_instrument D "measuring instrument" NT altimeter anemometer atomic_clock barometer chronometer clock counter densitometer heliometer microdensitometer micrometer microphotometer monochromator proportional_counter radiometer range_finder sensitometer weather_station wind_vane RT calibration measurement ## mechanical_component mechanical_component D "mechanical component" N "combine with other terms" ## mechanical_property mechanical_property D "mechanical property" BT property N "combine with other terms" ## medium_band_photometry medium_band_photometry D "medium-band photometry" BT CCD_photometry photoelectric_photometry NT DDO_photometry Geneva_photometry Stromgren_photometry Vilnius_photometry Walraven_photometry infrared_photometry ultraviolet_photometry RT broad_band_photometry narrow_band_photometry ## megalithic_astronomy megalithic_astronomy D "megalithic astronomy" BT archaeoastronomy ## megamaser megamaser D "megamaser" BT maser ## meitnerium meitnerium ALT "Mt" D "meitnerium (atomic number 109)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## mendelevium mendelevium ALT "Md" D "mendelevium (atomic number 101)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Mercury Mercury D "the planet Mercury" BT planet RT Solar_System HN "FVH: new (2007-SEP-24)" N "See mercury for the element rather than the planet." ## mercury_manganese_star mercury_manganese_star D "mercury manganese star" BT B_star magnetic_star RT manganese mercury ## mercury mercury ALT "Hg" D "mercury (atomic number 80)" BT fundamental_chemical_element RT mercury_manganese_star N "Don't get confused with the planet Mercury (2007-NOV-13)" ## merger merger D "merger" NT galaxy_merger ## meridian_circle meridian_circle D "meridian circle" BT transit_instrument RT astrometry meridian quadrant vertical_circle ## meridian meridian D "meridian" RT celestial_sphere horizon_coordinate_system meridian_circle meridian_observation HN "FVH: new (2007-OCT-3)" ## meridian_observation meridian_observation D "meridian observation" RT meridian transit_instrument transit_telescope transit_time zenith_telescope ## meson meson D "meson" BT boson elementary_particle RT photon quark ## mesopause mesopause D "mesopause" RT Earth_atmosphere ionosphere mesosphere thermosphere ## mesosphere mesosphere D "mesosphere" RT Earth_atmosphere mesopause stratopause upper_atmosphere ## Me_star Me_star D "Me star" BT M_star emission_line_star RT Me_variable_star late-type_variable_star ## metagalaxy metagalaxy D "metagalaxy" RT universe ## metal_abundance metal_abundance ALT "metallicity" D "metal abundance" BT abundance RT CNO_anomaly Oosterhoff_group chemical_element dredge_up helium-poor_star helium-rich_star hydrogen_deficient_star metal-deficient_star metal-poor_star metal-rich_star rare_earth trace_element ## metal-deficient_star metal-deficient_star D "metal-deficient star" BT star RT metal_abundance metal-poor_star ultraviolet_excess_star ## metal_line metal_line D "metal line" BT spectral_line NT Ca_II_emission_line calcium_line carbon_line technetium_line RT absorption_line line_blanketing rare_earth ## metal-poor_star metal-poor_star ALT "metal poor star" D "metal-poor star" BT star NT lithium-poor_star population_II_star population_III_star weak_G_band_star RT metal_abundance metal-deficient_star ultraviolet_excess_star CN "FVH: added NT POP II and III STARS (2007-SEP-21)" ## metal-rich_star metal-rich_star ALT "metallic line star" D "metal rich star" BT star NT Am_star silicon_star RT metal_abundance red_giant_bump ## meteor_camera meteor_camera D "meteor camera" NT Baker-Nunn_camera ## meteorite_crater meteorite_crater D "meteorite crater" RT meteorite_impact meteorite meteor ## meteorite_impact meteorite_impact D "meteorite impact" RT meteorite_crater meteorite meteor ## meteorite meteorite D "meteorite" BT meteor NT achondrite aerolite ataxite australite bediasite chondrite iron_meteorite micrometeorite moldavite tektite RT Neumann_line ablation asteroid collision comet impact_crater interplanetary_matter meteorite_crater meteorite_impact ## meteoroid_dust_cloud meteoroid_dust_cloud D "meteoroid dust cloud" RT asteroid comet meteoroid meteor zodiacal_dust ## meteoroid meteoroid ALT "meteorids" D "meteoroid" BT interplanetary_dust interplanetary_grain interplanetary_matter NT micrometeoroid RT asteroid comet meteoroid_dust_cloud meteor zodiacal_dust ## meteorology meteorology D "meteorology" RT Earth_atmosphere ## meteor_shower meteor_shower D "meteor shower" RT meteor_stream meteor_trail meteor radiant_meteor zenith_hourly_rate N "named shower not included" ## meteor meteor D "meteor" NT bolide fireball meteorite RT crater meteor_shower meteor_stream meteor_trail meteorite_crater meteorite_impact meteoroid_dust_cloud meteoroid radiant_meteor ## meteor_stream meteor_stream D "meteor stream" RT asteroid comet meteor_shower meteor_trail meteor radiant_meteor ## meteor_trail meteor_trail D "meteor trail" RT meteor_shower meteor_stream meteor radiant_meteor ## methane methane ALT "CH4" "CH_4" D "methane molecule" BT interstellar_molecule molecule RT molecular_cloud HN "FVH: new (2007-OCT-5)" ## metonic_cycle metonic_cycle D "metonic cycle" RT Saros_cycle lunar_phase ## metrology metrology D "metrology" RT instrument measurement unit ## Me_variable_star Me_variable_star D "Me variable star" BT M_giant emission_line_star late-type_variable_star RT Me_star ## M_giant M_giant D "M giant star" BT M_star giant late-type_giant NT Me_variable_star RT M_subgiant ## Michelson_interferometer Michelson_interferometer D "Michelson interferometer" BT optical_interferometer RT Michelson_interferometry intensity_interferometer ## Michelson_interferometry Michelson_interferometry D "Michelson interferometry" RT Michelson_interferometer optical_interferometry ## microchannel_plate microchannel_plate D "micro-channel plate" BT amplifier RT image_tube HN "FVH: new (2007-SEP-21)" ## microdensitometer microdensitometer D "microdensitometer" BT measuring_instrument RT densitometer microphotometer photograph ## microdensitometry microdensitometry D "microdensitometry" N "see microdensitometer" ## micrometeorite micrometeorite D "micrometeorite" BT meteorite RT interplanetary_matter ## micrometeoroid micrometeoroid D "micrometeoroid" BT meteoroid ## micrometer micrometer D "micrometer" BT measuring_instrument ## microphotometer microphotometer D "microphotometer" BT measuring_instrument RT microdensitometer photography ## microprocessor microprocessor D "microprocessor" BT computer RT control_system ## microturbulence microturbulence D "microturbulence" BT turbulence_Earth_atmosphere turbulence_star_atmosphere RT absorption_line atmosphere ## microwave_antenna microwave_antenna ALT "microwave antennas" D "microwave antennaa" BT antenna RT microwave_radiation ## microwave_background microwave_background D "cosmic microwave background" BT background_radiation cosmic_noise microwave_radiation RT Sunyaev-Zeldovich_effect X-ray_background cosmology gamma-ray_background radio_background ultraviolet_background CN "FVH: Added RT COSMOLOGY (2007-SEP-21)" ## microwave_emission microwave_emission D "microwave emission" BT emission_spectrum RT cosmic_noise ## microwave_imaging microwave_imaging D "microwave imaging" RT microwave_radiation ## microwave_radiation microwave_radiation D "microwave radiation" BT electromagnetic_radiation NT microwave_background RT microwave_antenna microwave_imaging millimeter_radiation remote_sensing ## microwave microwave D "microwave" RT millimeter_radiation N "combine with other terms" ## microwave_spectrum microwave_spectrum D "microwave spectrum" BT spectrum RT radio_spectrum ## microwave_spectroscopy microwave_spectroscopy D "microwave spectroscopy" BT spectroscopy ## Mie_scattering Mie_scattering D "Mie scattering" BT scattering RT Rayleigh_scattering brillouin_scattering ## Milky_Way_galaxy Milky_Way_galaxy ALT "the Galaxy" D "the Milky Way galaxy" BT galaxy Local_Group spiral_galaxy RT Galactic_anticenter Galactic_bulge Galactic_center Galactic_cluster Galactic_coordinate_system Galactic_cosmic_ray Galactic_equator Galactic_halo Galactic_latitude Galactic_longitude Galactic_plane Galactic_pole Galactic_rotation Goulds_belt high-velocity_cloud high-velocity_star sky_brightness ## millimeter_astronomy millimeter_astronomy D "millimeter astronomy" BT radio_astronomy RT radio_observatory satellite-borne_instrument submillimeter_astronomy ## millimeter_radiation millimeter_radiation ALT "millimeter wave" "mm radiation" D "millimeter radiation" BT electromagnetic_radiation RT microwave_radiation microwave CN "FVH: added BT electromagnetic_radiation (2007-OCT-8)" ## Mills_cross_antenna Mills_cross_antenna ALT "Mills cross antennas" D "Mills cross antenna" BT antenna directional_antenna radio_telescope RT pencil_beam ## Milne_Eddington_approximation Milne_Eddington_approximation D "Milne Eddington approximation" RT line_width spectroscopic_analysis ## mineral_deposit mineral_deposit D "mineral deposit" RT mineralogy ## mineralogy mineralogy D "mineralogy" RT mineral_deposit ## minimum minimum D "minimum" BT photometric_element RT light_curve maximum variable_star velocity_curve ## minor_axis minor_axis D "minor axis" BT semiminor_axis RT axial_ratio major_axis HN "ES: new (2007-OCT-11)" "see terms under major axis" ## minor_planet_family minor_planet_family D "minor planet family" NT Amor_group Apollo_group Hirayama_family Trojan_group RT asteroid N "not a complete list of terms" ## Mira_variable_star Mira_variable_star ALT "Miras" "omicron Ceti star" "zeta Aurigae star" D "Mira variable star" BT emission_line_star irregular_variable_star late-type_giant long_period_variable_star pulsating_variable_star RT S_Vulpeculae_star radial_pulsation semi-regular_variable_star ## mirror_cell mirror_cell D "mirror cell" RT mirror ## mirror mirror D "mirror" BT optical_component NT dichroic_mirror primary_mirror telescope_mirror RT aluminizing aluminum_coating catadioptric_system catoptric_system coating collimator figuring glass mirror_cell optical_aberration optical_instrument optical_material optical_surface polishing reflection thin_film ## missing_mass missing_mass D "missing mass" RT cosmology galaxy_cluster mass_to_light_ratio velocity_dispersion ## MK_classification MK_classification D "MK classification" BT spectral_classification NT luminosity_class RT luminosity spectrum ## M_magnitude M_magnitude D "M magnitude" BT apparent_magnitude RT far_infrared_radiation infrared_photometry ## model model D "model" NT computer_model orrery RT equilibrium_figures numerical_simulation polytrope simulation stellar_structure N "combine with other terms" ## MOdified_Newtonian_Dynamics MOdified_Newtonian_Dynamics ALT "MOND" D "MOdified Newtonian Dynamics" BT gravitation RT Newtonian_gravitation gravitational_effect gravitational_force ## modulation modulation D "modulation" N "combine with other terms" ## modulation_transfer_function modulation_transfer_function ALT "MTF" D "modulation transfer function" BT transfer_function RT optical_instrument optical_testing optical_transfer_function ## moldavite moldavite D "moldavite" BT meteorite tektite RT australite bediasite chondrite ## molecular_astrophysics molecular_astrophysics D "molecular astrophysics" RT cosmochemistry molecular_band molecular_line molecular_spectroscopy ## molecular_band molecular_band D "molecular band" BT spectral_band NT B_band G_band Phillips_band Swan_band RT late-type_star molecular_astrophysics molecular_line molecular_spectrum zirconium_star ## molecular_cloud molecular_cloud D "molecular cloud" BT interstellar_matter NT giant_molecular_cloud RT interstellar_molecule methane molecular_hydrogen ## molecular_hydrogen molecular_hydrogen D "molecular hydrogen" BT hydrogen interstellar_molecule molecule NT orthohydrogen parahydrogen RT molecular_cloud ## molecular_line molecular_line D "molecular line" BT spectral_line RT fine_structure late-type_star molecular_astrophysics molecular_band spectral_band ## molecular_spectrum molecular_spectrum D "molecular spectrum" BT spectrum NT Phillips_band p_branch RT B_band G_band Raman_spectroscopy Swan_band late-type_star molecular_band molecule organic_molecule q_branch spectral_band vibrational_spectrum ## molecular_spectroscopy molecular_spectroscopy D "molecular spectroscopy" RT molecular_astrophysics N "see molecular spectrum" ## molecule molecule D "molecule" BT matter NT hydrated_carbon interstellar_molecule methane molecular_hydrogen organic_molecule RT molecular_spectrum ## molybdenum molybdenum ALT "Mo" D "molybdenum (atomic number 42)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## momentum momentum D "momentum" RT angular_momentum mass velocity ## monochromator monochromator D "monochromator" BT measuring_instrument optical_instrument ## Monte_Carlo_technique Monte_Carlo_technique D "Monte Carlo technique" BT data_processing RT statistics ## Moon Moon D "Moon" BT satellite RT Earthshine anomalistic_month apogee crater crust crustal_dynamics equation_of_the_center libration lunar_dome lunar_eclipse lunar_laser_ranging lunar_occultation lunar_theory mantle maria mascon moonquake nutation occultation perigee phase_angle phase_defect ray regression_of_node selenology solar_eclipse surface_of_celestial_body N "Earth's satellite; see under satellite or planet for more rts; see also lunar" ## moonquake moonquake D "moonquake" RT Moon earthquake ## morphology morphology D "morphology" RT classification disk_flaring N "combine with other terms" ## motion motion D "motion" NT apparent_superluminal_motion apsidal_motion internal_motion orbital_motion polar_motion proper_motion solar_motion space_motion stellar_motion wave_motion RT orbit orrery planetarium N "combine with other terms" ## mottle mottle D "mottle" RT Sun chromosphere ## moving_cluster_parallax moving_cluster_parallax ALT "cluster parallax" D "moving cluster parallax" BT parallax RT dynamical_parallax kinematic_parallax open_star_cluster proper_motion radiant_moving_cluster secular_parallax ## m_region m_region D "m region" BT solar_corona ## M_star M_star D "M star" BT late-type_star NT M_dwarf M_giant M_subdwarf M_subgiant M_supergiant Me_star RT spectral_type titanium_oxide ## M_subdwarf M_subdwarf D "M subdwarf star" BT M_star subdwarf ## M_subgiant M_subgiant D "M subgiant star" BT M_star subgiant RT M_giant ## M_supergiant M_supergiant D "M supergiant star" BT M_star late-type_supergiant ## multi-channel_detector multi-channel_detector ALT "multichannel detector" D "multi-channel detector" BT detector NT CCD_detector diode_array image_tube reticon_array television_detector RT charge-coupled_device multi-channel_spectrograph ## multi-channel_spectrograph multi-channel_spectrograph ALT "multi-channel spectrometer" "multichannel spectrograph" D "multi-channel spectrograph" BT spectrograph RT multi-channel_detector ## multi-color_photometry multi-color_photometry ALT "multicolor photometry" D "multi-color photometry" BT photometry ## multi-fiber_spectrograph multi-fiber_spectrograph D "multi-fiber spectrograph" BT spectrograph RT integral_field_spectrograph optical_fiber three-dimensional_spectrum HN "FVH: new (2007-SEP-21)" ## multi-periodic_pulsation multi-periodic_pulsation ALT "multiperiodic pulsation" D "multi-periodic pulsation" NT double-mode_pulsation RT Fourier_analysis frequency_analysis multi-periodic_variable_star pulsating_variable_star pulsation_mode ## multi-periodic_variable_star multi-periodic_variable_star ALT "multiperiodic variable star" D "multi-periodic variable star" BT periodic_variable_star pulsating_variable_star NT PG1159_star RS_Canum_Venaticorum_star SX_Phoenicis_star ZZ_Ceti_star beta_Cephei_star delta_Scuti_star double-mode_variable_star dwarf_Cepheid RT multi-periodic_pulsation overtone_frequency overtone_mode pulsation_mode ## multiple_galaxy multiple_galaxy D "multiple galaxy" BT galaxy RT galaxy_cluster galaxy_group ## multiple_mirror_telescope multiple_mirror_telescope ALT "MMT" D "multiple mirror telescope" BT optical_telescope reflecting_telescope RT active_optics segmented_optics very_large_telescope ## multiple_star multiple_star D "multiple star" NT triple_star RT binary_star companion_star orbit_determination orbit CN "FVH: moved triple_star to NT (2007-OCT-1)" ## multi-slit_spectrograph multi-slit_spectrograph D "multi-slit spectrograph" BT spectrograph RT integral_field_spectrograph spectrograph_slit three-dimensional_spectrum HN "FVH: new (2007-SEP-21)" ## muon muon D "muon" BT lepton ## nadir nadir D "nadir" BT pole RT horizon_coordinate_system zenith ## naked_singularity naked_singularity D "naked singularity" BT singularity RT black_hole quantum_cosmology space-time_singularity white_hole ## narrow_band_photometry narrow_band_photometry D "narrow-band photometry" BT CCD_photometry photoelectric_photometry NT H_alpha_photometry H_beta_photometry RT broad_band_photometry medium_band_photometry ## Nasmyth_focus Nasmyth_focus D "Nasmyth focus" BT focus RT Cassegrain_focus Coude_focus Newtonian_focus prime_focus tertiary_mirror ## natural_line_broadening natural_line_broadening D "natural line broadening" BT line_broadening RT natural_line_width spectral_line ## natural_line_width natural_line_width D "natural line width" BT line_width RT Doppler_broadening Stark_broadening Zeeman_splitting line_broadening natural_line_broadening pressure_broadening spectral_line ## nautical_almanac nautical_almanac D "nautical almanac" BT almanac RT ephemeris ## Navarro-Frenk-White_profile Navarro-Frenk-White_profile ALT "NFW" "NFW profile" "NFW-profile" D "Navarro-Frenk-White mass-profile" BT mass_distribution RT Burkert_profile exponential_profile isothermal_sphere HN "FVH: new (2007-OCT-5)" ## N-body_problem N-body_problem ALT "N body problem" "many body problem" "many-body problem" D "N-body problem" RT N-body_simulation celestial_mechanics orbit perturbation stellar_dynamics three-body_problem two-body_problem ## N-body_simulation N-body_simulation D "N-body simulation" BT numerical_simulation RT N-body_problem HN "FVH: new (2007-OCT-3)" ## nearby_dwarf nearby_dwarf D "nearby dwarf star" BT dwarf nearby_star ## nearby_galaxy nearby_galaxy D "nearby galaxy" BT galaxy NT Magellanic_cloud Local_Group RT bright_galaxy ## nearby_star nearby_star D "nearby star" NT nearby_dwarf RT trigonometric_parallax ## near-Earth_asteroid near-Earth_asteroid ALT "NEO" "near Earth asteroid" "near-Earth object" D "near-Earth asteroid" BT asteroid ## near_infrared_radiation near_infrared_radiation D "near infrared radiation" BT infrared_radiation RT H_magnitude I_magnitude J_magnitude K_magnitude L_magnitude far_infrared_radiation infrared_photometry ## near_ultraviolet_radiation near_ultraviolet_radiation ALT "NUV" D "near ultraviolet radiation" BT ultraviolet_radiation RT extreme_ultraviolet_radiation far_ultraviolet_radiation ## nebula nebula D "nebula" BT interstellar_matter NT bipolar_nebula bright_nebula compact_nebula dark_nebula dense_cloud diffuse_nebula dust_nebula emission_nebula filamentary_nebula gaseous_nebula planetary_nebula reflection_nebula ring_nebula RT Opik_theory forbidden_line forbidden_transition nebular_filament surface_photometry N "named nebula not included; not including galaxy" ## nebular_filament nebular_filament D "nebular filament" BT interstellar_matter RT filamentary_nebula nebula ## negative_H_ion negative_H_ion ALT "H minus ion" "H-" "H- ion" D "negative hydrogen ion" BT hydrogen RT opacity stellar_atmosphere ## neighborhood neighborhood D "neighborhood" N "combine with other terms" ## neodymium neodymium ALT "Nd" D "neodymium (atomic number 60)" BT fundamental_chemical_element rare_earth HN "FVH: new (2007-OCT-25)" ## neon neon ALT "Ne" D "neon (atomic number 10)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Neptune Neptune D "Neptune" BT Jovian_planet planet RT Solar_System HN "FVH: new (2007-SEP-24)" ## neptunium neptunium ALT "Np" D "neptunium (atomic number 93)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Neumann_line Neumann_line D "Neumann line" RT emission_line emission_spectrum meteorite ## neutral_density_filter neutral_density_filter D "neutral density filter" BT filter RT attenuation HN "FVH: new (2007-SEP-21)" ## neutral_gas neutral_gas D "neutral gas" BT gas NT H_I He_I RT H_I_region ## neutrino neutrino D "neutrino" BT elementary_particle lepton particle RT antineutrino solar_neutrino_problem supernova ## neutron neutron D "neutron" BT elementary_particle fundamental_particle RT alpha_particle nucleus_atom ## neutron_star neutron_star D "neutron star" BT collapsed_star compact_object degenerate_star relativistic_star stellar_object NT HZ_Herculis_star magnetar RT Alfven_surface X-ray_binary_star X-ray_burst X-ray_pulsar low-mass_X-ray_binary_star pulsar quark relativistic_astrophysics supernova_remnant ## Newtonian_focus Newtonian_focus D "Newtonian focus" BT Newtonian_telescope focus RT Cassegrain_focus Coude_focus Nasmyth_focus ## Newtonian_gravitation Newtonian_gravitation D "Newtonian gravitation" BT gravitation RT MOdified_Newtonian_Dynamics general_theory_of_relativity gravitational_constant gravitational_force ## Newtonian_telescope Newtonian_telescope D "Newtonian telescope" NT Newtonian_focus ## N_galaxy N_galaxy D "N galaxy" BT compact_galaxy galaxy RT Yerkes_classification galactic_nucleus giant_radio_galaxy ## nickel nickel ALT "Ni" D "nickel (atomic number 28)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## night_sky_brightness night_sky_brightness ALT "night sky background" D "night sky brightness" BT sky_brightness RT Rayleigh Rayleigh_scattering airglow aurora gegenschein zodiacal_light ## night_vision night_vision D "night vision" RT dark_adaption ## niobium niobium ALT "Nb" D "niobium (atomic number 41)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## nitrogen nitrogen ALT "N" D "nitrogen (atomic number 7)" BT fundamental_chemical_element RT carbon_nitrogen_cycle HN "FVH: new (2007-OCT-25)" ## N_magnitude N_magnitude D "N magnitude" BT apparent_magnitude RT far_infrared_radiation infrared_photometry ## nobelium nobelium ALT "No" D "nobelium (atomic number 102)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## noctilucent_cloud noctilucent_cloud D "noctilucent cloud" BT cloud RT Earth_atmosphere luminescence N "in Earth's atmosphere" ## node node ALT "line of node" D "node" NT ascending_node descending_node RT inclination orbit vibration ## noise noise D "noise" NT background_noise cosmic_noise interference_noise read_out_noise shot_noise sky_noise RT integration_time signal-to-noise_ratio CN "FVH: moved interference_noise to NT (2007-OCT-1)" N "combine with other terms" ## nomenclature nomenclature D "nomenclature" RT catalog classification ## non-equilibrium_flow non-equilibrium_flow ALT "nonequilibrium flow" D "non-equilibrium flow" BT flow RT flow_instability ## non-LTE_transfer non-LTE_transfer ALT "nonLTE transfer" D "non-LTE transfer" RT energy-transfer local_thermodynamic_equilibrium radiation_mechanism ## non-main_sequence_star non-main_sequence_star ALT "nonmain_sequence star" D "non-main_sequence star" NT evolved_star post-main_sequence_star pre-main_sequence_star N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## non-radial_pulsation non-radial_pulsation ALT "nonradial pulsation" D "non-radial pulsation" RT ZZ_Ceti_star beta_Cephei_star delta_Scuti_star pulsating_variable_star pulsation_mode ## non-thermal_particle non-thermal_particle ALT "nonthermal particle" D "non-thermal particle" RT non-thermal_source ## non-thermal_radiation non-thermal_radiation ALT "nonthermal radiation" D "non-thermal radiation" RT non-thermal_source ## non-thermal_source non-thermal_source ALT "nonthermal source" D "non-thermal source" BT source RT non-thermal_particle non-thermal_radiation synchrotron_radiation ## North_Celestial_Pole North_Celestial_Pole D "North Celestial Pole" ALT "NCP" "N.C.P." BT celestial_pole RT South_Celestial_Pole ## North_Ecliptic_Pole North_Ecliptic_Pole D "North Ecliptic Pole" ALT "NEP" "N.E.P." BT ecliptic_pole RT South_Ecliptic_Pole ## northern_hemisphere northern_hemisphere D "northern hemisphere" RT southern_hemisphere ## North_Galactic_Pole North_Galactic_Pole D "North Galactic Pole" ALT "NGP" "N.G.P." BT Galactic_pole RT South_Galactic_Pole ## nova nova D "nova" BT eruptive_binary_star high-luminosity_star NT classical_nova X-ray_nova fast_nova recurrent_nova slow_nova symbiotic_nova RT mass-loss optical_outburst pre-nova progenitor supernova ## nova-like_variable nova-like_variable D "nova-like variable" BT cataclysmic_variable_star NT AM_Canum_Venaticorum_star UX_Ursae_Majoris_star VY_Sculpturis_star ## N_star N_star D "N star" BT late-type_star RT spectral_type technetium_star ## nuclear_astrophysics nuclear_astrophysics D "nuclear astrophysics" RT high-energy_astrophysics nuclear_physics ## nuclear_fission nuclear_fission D "nuclear fission" BT fission nuclear_reaction RT cosmochronology radioactivity ## nuclear_fusion nuclear_fusion D "nuclear fusion" BT fusion nuclear_reaction NT carbon_burning helium_burning oxygen_burning silicon_burning RT carbon_flash carbon_nitrogen_cycle e-process helium_flash helium_shell_flash hydrogen_burning proton-proton_reaction shell_burning stellar_interior supernova ## nuclear_physics nuclear_physics D "nuclear physics" RT interaction nuclear_astrophysics nuclear_radiation nuclear_reaction strong_interaction weak_interaction ## nuclear_radiation nuclear_radiation D "nuclear radiation" NT alpha_particle electron gamma-ray_radiation positron RT Cerenkov_radiation nuclear_physics ## nuclear_reaction nuclear_reaction D "nuclear reaction" NT nuclear_fission nuclear_fusion urca_process RT carbon_burning nuclear_physics nucleosynthesis solar_neutrino_problem ## nucleus_atom nucleus_atom D "nucleus [atom]" NT Bose-Einstein_nucleus Fermi-Dirac_nucleus RT neutron proton ## nucleus_celestial_object nucleus_celestial_object D "nucleus [celestial object]" NT compact_nucleus galactic_nucleus RT cD_galaxy comet dirty_snowball_theory N "combine with other terms" ## nucleosynthesis nucleosynthesis D "nucleosynthesis" NT carbon_burning helium_burning hydrogen_burning oxygen_burning silicon_burning RT nuclear_reaction p_process r-process s-process stellar_interior supernova ## numerical_analysis numerical_analysis D "numerical analysis" BT data_processing RT numerical_integration numerical_method numerical_simulation ## numerical_integration numerical_integration D "numerical integration" RT numerical_analysis numerical_method ## numerical_method numerical_method D "numerical method" RT numerical_analysis numerical_integration numerical_simulation ## numerical_simulation numerical_simulation D "numerical simulation" NT N-body_simulation SPH_simulation RT computer_model model numerical_analysis numerical_method ## nutation nutation D "nutation" RT Earth_rotation Moon equation_of_the_equinox polar_motion precession ## O_association O_association ALT "O-association" D "O association" BT star_association RT O_cluster OB_association ## OB_association OB_association D "OB association" BT star_association RT O_association young_star ## objective_grating objective_grating D "objective grating" BT diffraction_grating transmission_grating RT echelle_grating reflection_grating ## objective_prism objective_prism D "objective prism" BT prism RT Schmidt_telescope ## objective objective D "objective [optics]" NT primary_lens primary_mirror RT optical_telescope N "primary optics of telescope" ## oblateness oblateness D "oblateness" RT elliptical_galaxy equatorial_bulge planet rotation ## oblique_rotator oblique_rotator D "oblique rotator" RT Ap_star magnetic_star spectrum_variable_star ## obliquity_of_ecliptic obliquity_of_ecliptic ALT "obliquity" D "obliquity of ecliptic" RT celestial_equator ecliptic ecliptic_plane phase_defect precession ## observational_cosmology observational_cosmology D "observational cosmology" RT Hubble_law color-redshift_relation cosmological_distance_scale galaxy_count galaxy_distribution observation radio_source_count redshift redshift_distance_relation ## observation observation D "observation" NT CCD_observation optical_observation RT data_acquisition observational_cosmology observing_technique research N "combine with other terms" ## observatory observatory D "observatory" NT antarctic_observatory gamma-ray_observatory geophysical_observatory infrared_observatory optical_observatory radio_observatory space_observatory ultraviolet_observatory X-ray_observatory RT dome planetarium site_protection site_testing telescope N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## observing_technique observing_technique ALT "method of observation" D "observing technique" NT astrometry interferometry photometry polarimetry radio_astrometry radio_interferometry spectrophotometry spectroscopy RT astronomical_technique data_acquisition data_processing observation occultation photography N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## OB_star OB_star D "OB star" BT early-type_star young_star NT B_star O_star OB_supergiant RT runaway_star young_star_cluster ## OB_supergiant OB_supergiant D "OB supergiant star" BT OB_star early-type_supergiant NT B_supergiant O_supergiant ## occultation occultation D "occultation" NT asteroid_occultation lunar_occultation radio_occultation RT Moon angular_diameter binary_star diameter eclipse observing_technique planet transit CN "FVH: added asteroid_occultation and lunar_occultation (2007-OCT-8)" ## occulting_disk occulting_disk D "occulting disc" UK "occulting disk" RT separation visual_binary_star ## oceanography oceanography D "oceanography" RT ocean_tide ## ocean_tide ocean_tide D "ocean tide" BT tide RT oceanography ## O_cluster O_cluster D "O-star cluster" BT open_star_cluster RT B_star O_association O_star ## O_dwarf O_dwarf D "O dwarf star" BT O_star dwarf ## Oef_star Oef_star D "Oef star" BT O_star early-type_emission_star RT Of_star ## Oe_star Oe_star D "Oe star" BT O_star early-type_emission_star ## Of_star Of_star D "Of star" BT O_star early-type_emission_star RT Oef_star ## O_giant O_giant D "O giant star" BT O_star ## OH_absorption OH_absorption D "OH absorption" BT interstellar_absorption RT hydroxyl_radical ## OH_cloud OH_cloud D "OH cloud" BT interstellar_matter RT hydroxyl_radical ## OH_emission OH_emission D "OH emission" BT emission_spectrum RT hydroxyl_radical ## OH_IR_star OH_IR_star ALT "OH-IR star" D "OH/IR star" BT OH_source giant infrared_source RT OH_maser hydroxyl_radical variable_star ## OH_line OH_line D "OH line" RT hydroxyl_radical ## OH_maser OH_maser D "OH maser" BT maser RT OH_IR_star SiO_maser hydroxyl_radical water_maser N "subtype not included" ## OH_source OH_source D "OH source" BT radio_source NT OH_IR_star RT hydroxyl_radical ## old_star old_star D "old star" BT evolved_star NT population_II_star population_III_star pre-Galactic_star CN "FVH: added NT POPULATION_III_STARS (2007-SEP-21)" ## O_magnitude O_magnitude D "O magnitude" BT apparent_magnitude RT far_infrared_radiation infrared_photometry ## Omega_baryon Omega_baryon ALT "Omega(baryon)" D "Omega(baryon), the cosmological baryon mass-density fraction" BT Omega_parameter RT baryon mass_density HN "FVH: new (2007-OCT-24)" ## Omega_Lambda Omega_Lambda ALT "Omega(Lambda)" D "Omega(Lambda), the cosmological vacuum energy density fraction" BT Omega_parameter RT cosmological_constant energy_density HN "FVH: new (2007-OCT-24)" ## Omega_mass Omega_mass ALT "Omega(mass)" D "omega(mass), the cosmological matter density fraction" BT Omega_parameter RT mass_density HN "FVH: new (2007-OCT-24)" ## Omega_parameter Omega_parameter D "the cosmological density fraction parameter, Omega" BT cosmological_parameter NT Omega_baryon Omega_Lambda Omega_mass RT cosmology energy_density mass_density HN "FVH: new (2007-SEP-21)" ## on-line_system on-line_system ALT "on line system" D "on-line system" RT data_center data_processing ## Oort_cloud Oort_cloud ALT "Oort comet cloud" D "Oort cloud" RT comet trans-Neptunian_object ## Oort_constant Oort_constant D "Oort constant" BT astronomical_constant RT Galactic_rotation Galactic_structure ## Oort_formulae Oort_formulae ALT "Oort formulas" D "Oort formulae" RT Galactic_rotation Galactic_structure ## Oosterhoff_group Oosterhoff_group D "Oosterhoff group" RT RR_Lyrae_star globular_star_cluster metal_abundance ## opacity opacity D "opacity" BT optical_property NT Kramers_opacity Rosseland_opacity RT absorption atmosphere negative_H_ion optical_depth radiation radiative_transfer transparency ## open_star_cluster open_star_cluster D "open star cluster" BT star_cluster NT Galactic_cluster O_cluster young_star_cluster RT blue_straggler_star moving_cluster_parallax population_I_star radiant_moving_cluster spiral_arm star_association turnoff_point ## open_universe open_universe D "open universe" BT cosmology RT Big_Bang_theory closed_universe steady-state_theory ## Opik_theory Opik_theory D "Opik theory" RT nebula supernova ## opposition opposition D "opposition" RT conjunction quadrature synodic_period syzygy N "refers to planet position" ## optical_aberration optical_aberration ALT "aberration" D "aberration of optical image" NT astigmatism chromatic_aberration comatic_aberration distortion field_curvature spherical_aberration RT focus lens mirror optical_system optics telescope CN "FVH: renamed for more clarity (2007-OCT-3)" ## optical_burst optical_burst D "optical burst" BT burst RT X-ray_burst burster gamma-ray_burst radio_burst N "specifically from burster" ## optical_component optical_component D "optical component" NT corrector_plate diffraction_grating field_corrector grism interference_filter lens mirror optical_fiber optical_filter optical_waveguide optical_window N "not a complete list of terms" ## optical_depth optical_depth ALT "optical thickness" D "optical depth" RT absorption_coefficient gas_density opacity ## optical_design optical_design D "optical design" RT optical_instrument ## optical_double_star optical_double_star D "apparent optical double star" RT angular_separation N "use only for pair in chance alignment; refer also to visual binary star" ## optical_fiber optical_fiber ALT "glass fiber" D "optical fiber" BT optical_component optical_waveguide RT fiber_optics glass multi-fiber_spectrograph optical_instrument ## optical_film optical_film ALT "film [optical]" D "optical film" NT antireflection_coating thin_film RT dichroic_mirror interference_filter light_interference ## optical_filter optical_filter ALT "color filter" D "optical filter" BT filter optical_component NT interference_filter iodine_cell photographic_filter RT dichroic_mirror light_interference optical_window photometry ultraviolet_filter ## optical_flare optical_flare D "optical flare" BT flare RT flare_star prominence ## optical_glass optical_glass D "optical glass" BT glass optical_material RT optical_window ## optical_identification optical_identification ALT "optical counterparts" D "optical identification" RT X-ray_identification X-ray_source gamma-ray_source radio_source ## optical_instrument optical_instrument ALT "optical equipment" D "optical instrument" NT camera coronagraph monochromator optical_scanners photometer polarimeter seeing_monitor spectrograph telescope RT Hartmann_test collimator field_corrector lens mirror modulation_transfer_function optical_design optical_fiber optical_material optical_system optical_testing optical_transfer_function prism N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## optical_interferometer optical_interferometer ALT "stellar interferometer" D "optical interferometer" BT interferometer NT Michelson_interferometer intensity_interferometer RT long_baseline_interferometer ## optical_interferometry optical_interferometry ALT "light interferometry" "stellar interferometry" D "optical interferometry" BT interferometry RT Michelson_interferometry interference_fringe interference_wave light_interference long_baseline_interferometry ## optical_material optical_material D "optical material" NT glass optical_glass RT lens mirror optical_instrument ## optical_observation optical_observation D "optical observation" BT observation RT optical_observatory ## optical_observatory optical_observatory D "optical observatory" BT observatory NT Hubble_Space_Telescope RT optical_observation optical_telescope seeing_monitor ## optical_outburst optical_outburst D "optical outburst" BT outburst RT cataclysmic_variable_star flare_star nova supernova N "not from burster" ## optical_pathlength optical_pathlength D "optical pathlength" RT refractive_index ## optical_position optical_position D "optical position" RT astrometry ## optical_property optical_property D "optical property" BT property NT albedo brightness color opacity refractive_index RT brightness_temperature darkness isotropy light_polarization optics N "not a complete list of terms" ## optical_pulsar optical_pulsar D "optical pulsar" BT pulsar RT radio_pulsar ## optical_radar optical_radar D "optical radar" BT radar RT laser_ranging laser lunar_laser_ranging satellite_laser_ranging ## optical_scanners optical_scanners D "optical scanners" BT optical_instrument RT spectrophotometry ## optical_spectrograph optical_spectrograph ALT "optical spectrometer" D "optical spectrograph" BT spectrograph ## optical_spectroscopy optical_spectroscopy D "optical spectroscopy" BT spectroscopy ## optical_surface optical_surface D "optical surface" RT aluminum_coating antireflection_coating figuring lens mirror polishing silver_coating thin_film CN "FVH: renamed from optical_surface (2007-OCT-2)" ## optical_system optical_system D "optical system" NT catadioptric_system catoptric_system dioptric_system RT aperture chromatic_aberration comatic_aberration distortion field_curvature optical_aberration optical_instrument ## optical_telescope optical_telescope D "optical telescope" BT telescope NT automatic_patrol_telescope multiple_mirror_telescope reflecting_telescope refracting_telescope very_large_telescope RT catadioptric_system catoptric_system dioptric_system eyepiece objective optical_observatory secondary_mirror tertiary_mirror ## optical_testing optical_testing D "optical testing" RT figuring modulation_transfer_function optical_instrument optical_transfer_function ## optical_transfer_function optical_transfer_function ALT "OTF" D "optical transfer function" BT transfer_function RT modulation_transfer_function optical_instrument optical_testing ## optical_transmission_window optical_transmission_window D "optical transmission window through the atmosphere" BT atmospheric_window RT infrared_transmission_window radio_transmission_window CN "FVH: renamed to avoid confusion with optics (2007-NOV-2)" N "low absorption in atmosphere" ## optical_waveguide optical_waveguide D "optical waveguide" BT optical_component waveguide NT optical_fiber ## optical_window optical_window D "optical window [optics]" BT optical_component RT optical_filter optical_glass ## optics optics D "optics" NT active_optics adaptive_optics astronomical_optics fiber_optics RT adjustment angular_resolution collimation optical_aberration optical_property refractive_index resolution transmission N "combine with other terms" ## orbital_anomaly orbital_anomaly ALT "apparent anomaly" D "orbital_anomaly" BT orbital_element NT eccentric_anomaly mean_anomaly real_anomaly true_anomaly RT anomalistic_month anomalistic_year ## orbital_element orbital_element D "orbital element" NT apsis center_of_mass eccentricity inclination orbital_anomaly osculatory_element period position_angle semimajor_axis RT acceleration celestial_mechanics orbit regression_of_node CN "FVH: removed element_of_orbit (2007-SEP-24)" N "see also orbit" ## orbital_evolution orbital_evolution D "orbital evolution" RT celestial_mechanics ## orbital_motion orbital_motion D "orbital motion" BT motion RT celestial_mechanics circular_orbit orbital_velocity visual_binary_star ## orbital_theory orbital_theory D "orbital theory" RT celestial_mechanics ## orbital_velocity orbital_velocity D "orbital velocity" BT velocity RT angular_velocity escape_velocity orbital_motion orbit tangential_velocity ## orbit_determination orbit_determination D "orbit determination" RT binary_star multiple_star planet ## orbit orbit D "orbit" NT Keplerian_orbit elliptical_orbit geocentric_orbit heliocentric_orbit hyperbolic_orbit osculating_orbit parabolic_orbit periodic_orbit polar_orbit RT N-body_problem Roche_limit Schwarzschild_metric acceleration apsidal_motion apsis binary_star celestial_mechanics high-velocity_star Local_Standard_of_Rest motion multiple_star node orbital_element orbital_velocity parabolic_velocity period perturbation perturbation_theory planet position_angle synchronous_rotation three-body_problem trajectory N "see also orbital element" ## organic_matter organic_matter D "organic matter" NT organic_molecule ## organic_molecule organic_molecule D "organic molecule" BT molecule organic_matter RT interstellar_molecule molecular_spectrum ## orientation orientation D "orientation" RT adjustment alignment_optics collimation position_angle ## origin origin D "origin" RT Solar_System chemical_element element_formation galaxy life planet N "combine with other terms" ## orion_population_star orion_population_star D "orion population star" RT early-type_star pre-main_sequence_star ## orrery orrery D "orrery" BT model RT motion planetarium ## orthohydrogen orthohydrogen D "orthohydrogen" BT molecular_hydrogen RT parahydrogen ## orthoscopic_eyepiece orthoscopic_eyepiece D "orthoscopic eyepiece" BT eyepiece ## oscillating_universe oscillating_universe D "oscillating universe" BT cosmology RT Friedmann_universe ## oscillation oscillation D "oscillation" RT amplitude decay_oscillation e-folding_time pendulum wave N "combine with other terms" ## oscillator_strength oscillator_strength ALT "f value" "f-value" D "oscillator strength" RT g_value gf_value line_formation line_width transition_probability ## osculating_orbit osculating_orbit D "osculating orbit" BT orbit ## osculatory_element osculatory_element D "osculatory element" BT orbital_element RT celestial_mechanics perturbation ## osmium osmium ALT "Os" D "osmium (atomic number 76)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## O_star O_star D "O star" BT OB_star early-type_star young_star NT O_dwarf O_giant O_subdwarf O_supergiant Oe_star Oef_star Of_star RT O_cluster Wolf-Rayet_star early-type_variable_star spectral_type ## O_subdwarf O_subdwarf D "O subdwarf star" BT O_star subdwarf ## O_supergiant O_supergiant D "O supergiant star" BT O_star OB_supergiant early-type_supergiant supergiant ## outburst outburst D "outburst" BT burst flare NT optical_outburst RT high-state low-state ## outer_planet outer_planet D "outer planet" BT planet NT Jovian_planet RT inner_planet ## outgassing outgassing D "outgassing" RT cryogenics vacuum_technique ## overabundance overabundance D "overabundance" BT abundance RT underabundance HN "ES: new (2007-OCT-8)" ## overtone_frequency overtone_frequency ALT "harmonic overtones" "overtones" D "overtone frequency" RT Fourier_analysis fundamental_frequency harmonic_frequency multi-periodic_variable_star overtone_mode N "see sn for overtone mode; also see harmonic frequency" ## overtone_mode overtone_mode ALT "overtones" D "overtone mode" BT pulsation_mode RT fundamental_mode multi-periodic_variable_star overtone_frequency pulsating_variable_star N "of pulsation frequency, not Fourier component of non-sinusoidal variation" ## oxygen_burning oxygen_burning D "oxygen burning" BT nuclear_fusion nucleosynthesis RT carbon_burning helium_burning hydrogen_burning oxygen stellar_interior ## oxygen oxygen ALT "O" D "oxygen (atomic number 8)" BT fundamental_chemical_element RT oxygen_burning titanium_oxide HN "FVH: new (2007-OCT-25)" ## ozone_layer ozone_layer D "ozone layer" RT Earth_atmosphere ## pair_annihilation pair_annihilation D "pair annihilation" RT electron gamma-ray_radiation positron ## pair_production pair_production D "pair production" BT particle_production RT electron gamma-ray_radiation positron ## paleomagnetism paleomagnetism D "paleomagnetism" RT continental_drift geomagnetism magnetic_field ## palladium palladium ALT "Pd" D "palladium (atomic number 46)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## parabolic_antenna parabolic_antenna ALT "parabolic antennas" D "parabolic antenna" BT antenna directional_antenna RT Cassegrain_focus ## parabolic_mirror parabolic_mirror D "parabolic mirror" RT parabolic_reflector N "see parabolic reflector" ## parabolic_orbit parabolic_orbit D "parabolic orbit" BT orbit RT circular_orbit comet elliptical_orbit hyperbolic_orbit ## parabolic_reflector parabolic_reflector D "parabolic reflector" RT dish_antenna parabolic_mirror radar_telescope radio_telescope reflecting_telescope ## parabolic_velocity parabolic_velocity D "parabolic velocity" BT velocity RT escape_velocity orbit ## parahydrogen parahydrogen D "parahydrogen" BT molecular_hydrogen RT orthohydrogen ## parallax parallax D "parallax" NT annual_parallax diurnal_parallax dynamical_parallax kinematic_parallax moving_cluster_parallax photometric_parallax secular_parallax statistical_parallax trigonometric_parallax RT Astronomical_Unit astrometry distance distance_modulus ## parallel_computer parallel_computer D "parallel computer" BT computer HN "FVH: new (2007-SEP-21)" ## parametric_amplifier parametric_amplifier D "parametric amplifier" BT amplifier ## parsec parsec ALT "parallax second" D "parsec" RT Astronomical_Unit distance distance_scale light_year ## partial_eclipse partial_eclipse D "partial eclipse" BT eclipse RT eclipsing_binary_star total_eclipse ## particle_acceleration particle_acceleration D "particle acceleration" RT elementary_particle ## particle_accretion particle_accretion D "particle accretion" RT accretion ## particle_beam particle_beam D "particle beam" RT high-energy_astrophysics ## particle_creation particle_creation D "particle creation" RT elementary_particle ## particle_escape particle_escape D "particle escape" RT elementary_particle ## particle_interaction particle_interaction D "particle interaction" RT elementary_particle ## particle_production particle_production D "particle production" NT pair_production RT elementary_particle ## particle_propagation particle_propagation D "particle propagation" ## particle particle D "particle" NT alpha_particle boson electron elementary_particle fundamental_particle ion lepton neutrino plasma positron proton relativistic_particle N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## Paschen-Back_effect Paschen-Back_effect D "Paschen-Back effect" RT Zeeman_splitting magnetic_field ## Paschen_series Paschen_series ALT "Paschen line" D "Paschen series" BT hydrogen_spectrum RT Balmer_series Brackett_series Lyman_series Pfund_series ## past_light_cone past_light_cone D "past light cone" BT light_cone RT future_light_cone ## Paul_trap Paul_trap D "Paul trap" RT electric_field ion radio_frequency ## p_branch p_branch D "p-branch" BT molecular_spectrum ## P_Cygni_line_profile P_Cygni_line_profile D "P Cygni line profile" BT line_profile RT S_Doradus_star emission_line_star mass-loss shell_star symbiotic_star ## peculiar_galaxy peculiar_galaxy D "peculiar galaxy" BT galaxy peculiar_object NT Ep_galaxy Seyfert_galaxy compact_galaxy dwarf_galaxy emission_line_galaxy interacting_galaxy ring_galaxy RT Markarian_galaxy ## peculiar_giant peculiar_giant D "peculiar giant star" BT giant peculiar_star ## peculiar_motion peculiar_motion D "peculiar motion" RT Local_Standard_of_Rest peculiar_velocity proper_motion radial_velocity stellar_motion ## peculiar_object peculiar_object D "peculiar object" NT peculiar_galaxy peculiar_star N "combine with other terms" ## peculiar_star peculiar_star D "peculiar star" BT peculiar_object NT Ap_star Bp_star heavy_metal_star holmium_star magnetic_star peculiar_giant peculiar_variable_star RT abnormal_spectrum abundance chemical_composition emission_line_star N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## peculiar_variable_star peculiar_variable_star D "peculiar variable star" BT peculiar_star variable_star ## peculiar_velocity peculiar_velocity D "peculiar velocity" BT velocity RT Local_Standard_of_Rest peculiar_motion radial_velocity stellar_motion ## pencil_beam pencil_beam D "pencil beam" RT Mills_cross_antenna radio_interferometer ## pendulum pendulum D "pendulum" BT timing_equipment RT geodesy gravity oscillation ## Penrose_process Penrose_process D "Penrose process" RT black_hole ## penumbra penumbra ALT "penumbras" D "penumbra" RT Wilson_effect eclipse lunar_eclipse penumbral_filament solar_eclipse sunspot umbra ## penumbral_filament penumbral_filament D "penumbral filament" RT penumbra ## periapsis periapsis D "periapsis" RT periastron perihelion ## periastron periastron D "periastron" BT apsis RT apastron periapsis ## pericenter pericenter D "pericenter" RT center_of_mass ## perigee perigee D "perigee" BT apsis RT Earth Moon apogee ## perihelion perihelion D "perihelion" BT apsis RT Earth_orbit aphelion periapsis planet ## period-age_relation period-age_relation ALT "period age relation" D "period-age relation" BT statistical_relation RT Cepheid period-color_relation period-density_relation period-luminosity-color_relation period-luminosity_relation period-mass_relation period-radius_relation period-spectrum_relation ## period_change period_change ALT "period variation" D "period change" RT binary_star pulsating_variable_star ## period-color_relation period-color_relation ALT "period color relation" D "period-color relation" BT statistical_relation RT Cepheid period-age_relation period-density_relation period-luminosity-color_relation period-luminosity_relation period-mass_relation period-radius_relation period-spectrum_relation pulsating_variable_star radius-luminosity_relation ## period-density_relation period-density_relation ALT "period density relation" D "period-density relation" BT statistical_relation RT period-age_relation period-color_relation period-luminosity-color_relation period-luminosity_relation period-mass_relation period-radius_relation period-spectrum_relation pulsating_variable_star radius-luminosity_relation ## period_determination period_determination D "period determination" RT binary_star variable_star waveform_analysis ## periodic_comet periodic_comet D "periodic comet" BT comet ## periodic_orbit periodic_orbit D "periodic orbit" BT orbit NT elliptical_orbit ## periodic_variable_star periodic_variable_star D "periodic variable star" BT pulsating_variable_star rotating_star NT multi-periodic_variable_star HN "FVH: new (2007-OCT-8)" ## period-luminosity-color_relation period-luminosity-color_relation ALT "PLC relation" "period luminosity color relation" D "period-luminosity-color relation" BT statistical_relation RT Cepheid period-age_relation period-color_relation period-density_relation period-luminosity_relation period-mass_relation period-radius_relation period-spectrum_relation pulsating_variable_star radius-luminosity_relation ## period-luminosity_relation period-luminosity_relation ALT "PL relation" "period luminosity relation" D "period-luminosity relation" BT statistical_relation RT Cepheid period-age_relation period-color_relation period-density_relation period-luminosity-color_relation period-mass_relation period-radius_relation period-spectrum_relation pulsating_variable_star radius-luminosity_relation ## period-mass_relation period-mass_relation ALT "period mass relation" D "period-mass relation" BT statistical_relation RT period-age_relation period-color_relation period-density_relation period-luminosity-color_relation period-luminosity_relation period-radius_relation period-spectrum_relation pulsating_variable_star radius-luminosity_relation ## period period D "period" BT orbital_element photometric_element RT binary_star cycle light_curve orbit phase_wave planet pulsating_variable_star pulsation_mode rotation variable_star velocity_curve ## period-radius_relation period-radius_relation ALT "period radius relation" D "period-radius relation" BT statistical_relation RT Cepheid period-age_relation period-color_relation period-density_relation period-luminosity-color_relation period-luminosity_relation period-mass_relation period-spectrum_relation pulsating_variable_star radius-luminosity_relation ## period-spectrum_relation period-spectrum_relation ALT "period spectrum relation" D "period-spectrum relation" BT statistical_relation RT Cepheid period-age_relation period-color_relation period-density_relation period-luminosity-color_relation period-luminosity_relation period-mass_relation period-radius_relation pulsating_variable_star radius-luminosity_relation ## peripheral peripheral D "peripheral" RT computer instrument N "combine with other terms" ## perturbation perturbation D "perturbation" RT N-body_problem celestial_mechanics orbit osculatory_element perturbation_theory three-body_problem ## perturbation_theory perturbation_theory D "perturbation theory" RT celestial_mechanics gravitation orbit perturbation ## petrology petrology D "petrology" BT geology RT planet surface_of_celestial_body ## Pfund_series Pfund_series D "Pfund series" BT hydrogen_spectrum infrared_radiation RT Balmer_series Brackett_series Lyman_series Paschen_series ## PG1159_star PG1159_star ALT "GW Virginis star" "PG1159-35 star" D "PG1159 star" BT DO_star multi-periodic_variable_star HN "ES: new (2007-OCT-8)" ## phase_angle phase_angle D "phase angle" RT Moon lunar_phase planet ## phased_array phased_array D "phased array" BT array RT phase_wave radio_interferometer ## phase_defect phase_defect D "phase defect" RT Moon lunar_phase obliquity_of_ecliptic ## phase_difference phase_difference D "phase difference" RT phase_wave ## phase_effect phase_effect D "phase effect" RT lunar_phase ## phase_error phase_error D "phase error" RT phase_wave ## phase_function phase_function D "phase function" RT phase_wave radiation_scattering ## phase_rotator phase_rotator D "phase rotator" RT phase_wave radio_telescope ## phase_sensitive_detector phase_sensitive_detector D "phase sensitive detector" RT phase_switching_interferometer phase_wave receiver ## phase_shift phase_shift ALT "phase-shift" D "phase shift" RT light_curve phase_wave variable_star velocity_curve ## phase_space phase_space D "phase space" RT phase_wave velocity_space ## phase_switching_interferometer phase_switching_interferometer D "phase switching interferometer" BT interferometer RT phase_sensitive_detector phase_wave ## phase_switching phase_switching D "phase switching" RT phase_wave radio_telescope receiver ## phase_wave phase_wave D "phase of a repeating wave" RT binary_star light_curve period phase_difference phase_error phase_function phase_rotator phase_sensitive_detector phase_shift phase_space phase_switching phase_switching_interferometer phased_array variable_star velocity_curve ## Phillips_band Phillips_band D "Phillips band" BT infrared_radiation molecular_band molecular_spectrum ## phosphorescence phosphorescence D "phosphorescence" RT image_tube phosphorescent_scintillation phosphorus scintillation_counter ## phosphorescent_scintillation phosphorescent_scintillation D "phosphorescent scintillation" BT scintillation RT cosmic_ray_shower image_tube phosphorescence scintillation_counter ## phosphorus phosphorus ALT "P" D "phosphorus (atomic number 15)" BT fundamental_chemical_element RT phosphorescence HN "FVH: new (2007-OCT-25)" ## photocathode photocathode D "photocathode" BT cathode electrode RT image_tube photomultiplier_tube ## photochemistry photochemistry D "photochemistry" RT photographic_developer photographic_material photographic_processing ## photoconductive_cell photoconductive_cell D "photoconductive cell" RT photomultiplier_tube ## photodiode photodiode D "photodiode" BT photoelectronic_device NT avalanche_photodiode RT photometry ## photodissociation photodissociation D "photodissociation" RT absorption ## photoelectric_instrument photoelectric_instrument D "photoelectric instrument" NT image_tube photomultiplier_tube ## photoelectric_magnitude photoelectric_magnitude D "photoelectric magnitude" BT apparent_magnitude RT photographic_magnitude photovisual_magnitude ## photoelectric_photometer photoelectric_photometer D "photoelectric photometer" BT photometer ## photoelectric_photometry photoelectric_photometry D "photoelectric photometry" BT photometry NT broad_band_photometry medium_band_photometry narrow_band_photometry RT CCD_photometry photographic_photometry ## photoelectronic_device photoelectronic_device D "photoelectronic device" NT avalanche_photodiode charge-coupled_device charge-injection_device charge-transfer_device image_tube photodiode photomultiplier_tube television_detector ## photogrammetry photogrammetry D "photogrammetry" RT map photograph photography ## photographic_astrometry photographic_astrometry D "photographic astrometry" BT astrometry RT proper_motion ## photographic_developer photographic_developer D "photographic developer" RT photochemistry photographic_processing photograph ## photographic_emulsion photographic_emulsion D "photographic emulsion" BT detector photographic_material RT halation photographic_film photographic_plate photograph photography quantum_efficiency turbidity ## photographic_film photographic_film ALT "film [photographic]" D "photographic film" BT photographic_material RT photographic_emulsion photograph photography ## photographic_filter photographic_filter D "photographic filter" BT optical_filter ## photographic_instrument photographic_instrument D "photographic instrument" NT Schmidt_camera Schmidt_telescope camera ## photographic_magnitude photographic_magnitude D "photographic magnitude" BT apparent_magnitude RT photoelectric_magnitude photovisual_magnitude ## photographic_material photographic_material D "photographic material" NT photographic_emulsion photographic_film photographic_plate RT photochemistry photograph ## photographic_photometry photographic_photometry D "photographic photometry" BT photometry NT broad_band_photometry RT CCD_photometry photoelectric_photometry ## photographic_plate photographic_plate D "photographic plate" BT photographic_material RT photographic_emulsion photograph photography reseaux ## photographic_processing photographic_processing D "photographic processing" RT darkroom photochemistry photographic_developer photography unsharp_masking ## photograph photograph D "photograph" BT image RT camera microdensitometer photogrammetry photographic_developer photographic_emulsion photographic_film photographic_material photographic_plate ## photography photography ALT "astrophotography" D "photography" NT all-sky_photography color_photography false_color_photography spectrography streak_photography ultraviolet_photography RT HD_curve astronomical_technique camera darkroom edge_effect image microphotometer observing_technique photogrammetry photographic_emulsion photographic_film photographic_plate photographic_processing unsharp_masking ## photoheliograph photoheliograph D "photoheliograph" RT spectroheliograph ## photoionization photoionization ALT "photoionisation UK" D "photoionization" BT ionization RT absorption aurora electron recombination ## photoluminescence photoluminescence D "photoluminescence" BT light_emission NT X-ray_fluorescence RT fluorescence ## photometer photometer D "photometer" BT optical_instrument telescope_instrument NT high-speed_photometer photoelectric_photometer spectrophotometer RT CCD_detector bolometer infrared_detector photometry photomultiplier_tube polarimeter radiometer ultraviolet_detector ## photometric_element photometric_element D "photometric element" NT light_curve maximum minimum period RT eclipsing_binary_star ## photometric_parallax photometric_parallax D "photometric parallax" BT parallax RT photometry ## photometric_standard_star photometric_standard_star D "photometric standard star" BT standard_star RT photometry standard_candle ## photometric_system photometric_system D "photometric system" NT Bessel_photometry Cape_photometry DDO_photometry Geneva_photometry Gunn_photometry HST_photometry Johnson_photometry Kron-Cousins_photometry Sloan_photometry Stromgren_photometry Walraven_photometry rgb_photometry RT apparent_magnitude photometry ## photometry photometry ALT "filter photometry" D "photometry" BT astronomical_technique observing_technique NT CCD_photometry infrared_photometry multi-color_photometry photoelectric_photometry photographic_photometry surface_photometry ultraviolet_photometry RT Purkinje_effect apparent_magnitude automatic_patrol_telescope avalanche_photodiode color color_equation color_excess color_index color-luminosity_relation color-magnitude_relation drift_scan e_region effective_temperature f_region interference_filter intrinsic_color magnitude optical_filter photodiode photometer photometric_parallax photometric_standard_star photometric_system polarimetry spectrophotometry standard_candle two-color_diagram N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## photomultiplier_tube photomultiplier_tube ALT "photocell" "photoelectric cell" D "photomultiplier tube" BT detector photoelectric_instrument photoelectronic_device RT amplifier cathode electrode photocathode photoconductive_cell photometer quadrant_detector quantum_efficiency scintillation_counter ## photon_counting_system photon_counting_system D "photon counting system" RT counter ## photon photon D "photon" BT boson elementary_particle RT electromagnetic_radiation inverse_Compton_effect inverse_Compton_scattering meson quanta radiation radiation_pressure radiation_scattering radiative_recombination ## photosphere photosphere ALT "reversing layer" D "photosphere" RT Sun chromosphere continuum_radiation facula granulation granule solar_surface surface_brightness surface_of_celestial_body N "ALT reversing_layer seems old-fashioned (IAU)!" ## photovisual_magnitude photovisual_magnitude D "photovisual magnitude" BT apparent_magnitude RT V_magnitude photoelectric_magnitude photographic_magnitude visual_magnitude ## photovoltaic_cell photovoltaic_cell D "photovoltaic cell" BT semiconductor_device ## physical_constant physical_constant ALT "fundamental constant" D "physical constant" BT constant NT Planck_constant gravitational_constant velocity_of_light RT astronomical_constant CN "FVH: renamed (see constant) (2007-OCT-11)" ## pion pion D "pion" BT boson elementary_particle ## pitch_angle pitch_angle D "pitch angle" RT Galactic_structure galaxy_structure spiral_arm spiral_galaxy ## pixel pixel ALT "picture element" "voxel" D "pixel" RT detector resolution two-dimensional_detector ## plage plage D "flocculi" "plage" "solar plage" RT chromosphere facula sunspot ## Planck_black_body_formula Planck_black_body_formula D "Planck black body formula" RT Planck_constant electromagnetic_radiation radiation ## Planck_constant Planck_constant D "Planck's constant h" BT physical_constant RT Planck_black_body_formula ## plane_polarization plane_polarization ALT "linear polarization" "plane polarisation UK" D "plane polarization" BT light_polarization RT circular_polarization half-wave_plate CN "FVH: added ALT linear polarization (2007-SEP-21)" ## planetarium planetarium D "planetarium" RT motion observatory orrery ## planetar planetar D "planetar" BT stellar_object RT brown_dwarf planet HN "FVH: new (2007-OCT-12)" ## planetary_alignment planetary_alignment D "alignment of planet, etc." RT Solar_System celestial_mechanics planet ## planetary_microlensing planetary_microlensing D "microlensing of exoplanet" BT gravitational_microlensing RT planet HN "FVH: new (2007-OCT-8)" ## planetary_nebula planetary_nebula D "planetary nebula" BT emission_nebula evolved_star nebula RT Harman-Seaton_sequence ansa central_star emission_line_star exciting_star mass-loss ring_nebula ## planetary planetary D "planetary" N "see sn for planet" ## planetary_ring planetary_ring D "planetary ring" BT ring RT Roche_limit planet resonance_gap ring_division shepherd_satellite ## planetary_system planetary_system D "planetary system" NT Solar_System ## planetary_theory planetary_theory D "planetary theory" RT Solar_System celestial_mechanics ## planetesimal planetesimal D "planetesimal" RT Solar_System asteroid planet protoplanet satellite ## planetology planetology D "planetology" RT geology ## planet_satellite planet_satellite D "planet satellite" BT satellite ## planet planet D "planet" BT rotating_body NT Earth Jupiter Mars Mercury Neptune Saturn Uranus Venus extrasolar_planet giant_planet hypothetical_planet inner_planet outer_planet RT Bodes_law Roche_limit Solar_System aeronomy aphelion astrology atmosphere boundary_layer center_of_mass collision composition core crater crust dust_storm dwarf_planet equatorial_bulge evolution exosphere galilean_satellite geology geomagnetism greenhouse_effect interior lithosphere mantle map mean_equinox oblateness occultation orbit_determination orbit origin perihelion period petrology phase_angle planetar planetary_alignment planetary_microlensing planetary_ring planetesimal polar_cap polar_region protoplanet resonance_gap rill ring_division satellite semimajor_axis solar_nebula solar-planetary_relation space_exploration structure surface_of_celestial_body synodic_period syzygy topography two-body_problem volatile volcano water_ice water_vapor CN "FVH: added lots of planet, RT DWARF_PLANETS (2007-SEP-24)" N "combine either planet or planetary with other terms" ## plasma_cloud plasma_cloud D "plasma cloud" BT cloud RT ion plasma_jet plasma ## plasma_jet plasma_jet D "plasma jet" BT jet RT ion plasma_cloud plasma_loop plasma ## plasma_loop plasma_loop D "plasma loop" RT plasma_jet plasma ## plasmapause plasmapause D "plasmapause" RT plasma ## plasma_physics plasma_physics D "plasma physics" RT magnetohydrodynamics plasma ## plasma plasma ALT "cosmic plasma" D "plasma" BT particle NT collisional_plasma low-temperature_plasma relativistic_plasma solar_wind stellar_wind RT H_II_region Holtsmark_approximation elementary_particle energetic_particle ionized_gas ion plasma_cloud plasma_jet plasma_loop plasma_physics plasma_wave plasmapause radiation_belt radiative_recombination thermodynamics viscosity ## plasma_wave plasma_wave D "plasma wave" RT ion_plasma_wave magnetohydrodynamics plasma ## platinum platinum ALT "Pt" D "platinum (atomic number 78)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Pluto Pluto D "Pluto" BT dwarf_planet RT Solar_System HN "FVH: new (2007-OCT-2)" ## plutonium plutonium ALT "Pu" D "plutonium (atomic number 94)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## P_magnitude P_magnitude D "P magnitude" BT apparent_magnitude RT far_infrared_radiation infrared_photometry ## Pogson_scale Pogson_scale D "Pogson scale" RT magnitude ## Poincare_theorem Poincare_theorem D "Poincare theorem" RT star_cluster stellar_dynamics ## pointing_accuracy pointing_accuracy D "pointing accuracy" RT control_system pointing_error telescope tracking ## pointing_error pointing_error D "pointing error" RT control_system pointing_accuracy telescope tracking ## point_spread_function point_spread_function ALT "PSF" D "point spread function" BT transfer_function RT atmospheric_refraction seeing turbulence_Earth_atmosphere ## polar_axis polar_axis D "polar axis" RT celestial_pole telescope_mounting ## polar_cap polar_cap D "polar cap" RT Earth planet ## polar_diagram polar_diagram D "polar diagram" RT antenna_design beamwidth radio_antenna sensitivity sidelobe ## polarimeter polarimeter D "polarimeter" BT optical_instrument telescope_instrument RT photometer polarimetry ## polarimetry polarimetry D "polarimetry" BT astronomical_technique observing_technique RT light_polarization photometry polarimeter ## polarization_charge_separation polarization_charge_separation D "polarization [charge separation]" BT magneto-optical_effect RT anisotropy ion ## polarized_light polarized_light ALT "polarised light UK" D "polarized light" BT electromagnetic_radiation visible_radiation RT light_polarization ## polarized_radiation polarized_radiation D "polarized radiation" BT electromagnetic_radiation radiation RT Faraday_effect X-ray_polarization light_polarization stokes_parameter ## polar_motion polar_motion D "polar motion" BT motion RT Chandler_wobble Earth_rotation latitude_variation nutation precession ## polar_orbit polar_orbit D "polar orbit" BT orbit RT artificial_satellite ## polar_region polar_region D "polar region" RT planet ## polar_tide polar_tide D "polar tide" BT tide ## pole pole D "pole" NT Galactic_pole celestial_pole ecliptic_pole nadir zenith ## polishing polishing D "polishing" NT figuring RT lens mirror optical_surface ## pollution pollution D "pollution" NT air_pollution light_pollution space_pollution RT greenhouse_effect site_testing ## polonium polonium ALT "Po" D "polonium (atomic number 84)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## polycyclic_hydrocarbon polycyclic_hydrocarbon D "polycyclic hydrocarbon" BT hydrocarbon ## polytrope polytrope D "polytrope" RT model stellar_structure ## population_II_Cepheid population_II_Cepheid D "Population II Cepheid" BT population_II_star NT RR_Lyrae_star W_Virginis_star ## population_III_star population_III_star ALT "PopIII" D "Population III star" BT metal-poor_star old_star star NT halo_star RT Galactic_halo globular_star_cluster stellar_population HN "FVH: new (2007-SEP-21)" ## population_II_star population_II_star ALT "Pop II star" "PopII" D "Population II star" BT metal-poor_star old_star star NT SX_Phoenicis_star disk_population disk_star halo_star horizontal_branch_star population_II_Cepheid RT Galactic_halo galactic_nucleus globular_star_cluster intermediate_population_star stellar_population subluminous_star ## population_inversion population_inversion D "population inversion" RT atomic_process laser maser stimulated_emission ## population_I_star population_I_star ALT "PopI" D "Population I star" BT star NT extreme_population_I_star young_star RT open_star_cluster spiral_arm stellar_population young_star_cluster ## position_angle position_angle D "position angle" BT orbital_element RT binary_star orbit orientation ## position_sensitive_proportional_counter position_sensitive_proportional_counter ALT "PSPC" D "position-sensitive proportional counter" BT proportional_counter HN "FVH: new (2007-SEP-21)" ## position position D "position" NT apparent_position true_position RT coordinate_system fundamental_system reference_system spherical_coordinate standard_star N "combine with other terms" ## positron positron D "positron" BT antiparticle lepton nuclear_radiation particle RT electron pair_annihilation pair_production radioactivity ## post-asymptotic_giant_branch post-asymptotic_giant_branch ALT "post-AGB" D "post-asymptotic giant branch" NT UU_Herculis_star RT Hertzsprung-Russell_diagram asymptotic_giant_branch late-type_giant HN "APM: new (2007-OCT-4)" ## post-main_sequence_star post-main_sequence_star ALT "post main sequence star" D "post-main sequence star" BT evolved_star non-main_sequence_star NT giant subgiant supergiant N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list; excluding advanced evolution" ## potassium potassium ALT "K" D "potassium (atomic number 19)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## potential_energy potential_energy D "potential energy" BT energy RT kinetic_energy ## potential_theory potential_theory D "potential theory" N "in mathematics" ## power power D "power" N "combine with other terms" ## Poynting-Robertson_effect Poynting-Robertson_effect ALT "Poynting Robertson effect" D "Poynting-Robertson effect" RT radiation_pressure solar_wind stellar_wind ## p_process p_process D "p-process" RT nucleosynthesis r-process s-process supernova ## praseodymium praseodymium ALT "Pr" D "praseodymium (atomic number 59)" BT fundamental_chemical_element rare_earth HN "FVH: new (2007-OCT-25)" ## preamplifier preamplifier D "preamplifier" BT amplifier ## precession precession D "precession" RT Earth_rotation astrometry celestial_mechanics equation_of_the_equinox nutation obliquity_of_ecliptic polar_motion superhump ## precision precision D "precision" RT limiting_magnitude sensitivity N "combine with other terms" ## precursor_pulse precursor_pulse D "precursor pulse" RT pulsar ## prediction prediction D "prediction" RT forecasts N "combine with other terms" ## pre-Galactic_star pre-Galactic_star ALT "pregalactic star" D "pre-Galactic star" BT old_star ## pre-main_sequence_star pre-main_sequence_star ALT "early stage star" "premainsequence star" D "pre-main sequence star" BT non-main_sequence_star young_star NT Herbig-Haro_object RW_Aurigae_star T_Tauri_star flash_star protostar RT T_association orion_population_star star_formation ## pre-nova pre-nova D "pre-nova" ALT "prenova" BT progenitor RT nova ## pre-solar_nebula pre-solar_nebula ALT "presolar nebula" D "pre-solar nebula" RT Solar_System ## pressure_broadening pressure_broadening D "pressure broadening" BT line_broadening RT Doppler_broadening Zeeman_splitting line_spectrum natural_line_width spectroscopy ## pressure pressure D "pressure" RT Rankine-Hugoniot_relation barometer radiation_pressure vacuum N "combine with other terms" ## pre-supernova pre-supernova ALT "presupernova" D "pre-supernova" BT progenitor RT supernova ## primary_lens primary_lens D "primary lens" BT lens objective RT refracting_telescope ## primary_mirror primary_mirror D "primary mirror" BT mirror objective telescope_mirror RT reflecting_telescope secondary_mirror tertiary_mirror ## primary_star primary_star D "primary star" BT companion_star RT secondary_star tertiary_star HN "ES: new (2007-OCT-8)" ## prime_focus prime_focus D "prime focus" BT focus RT Cassegrain_focus Coude_focus Nasmyth_focus ## primordial_fireball primordial_fireball D "primordial fireball" BT cosmology RT Big_Bang_theory ## primordial_galaxy primordial_galaxy D "primordial galaxy" BT galaxy ## prism_spectrograph prism_spectrograph D "prism spectrograph" BT spectrograph RT grating_spectrograph prism ## prism prism D "prism" NT objective_prism RT grism optical_instrument prism_spectrograph spectrum spectrograph ## profile profile D "profile" NT line_profile ## progenitor progenitor ALT "precursors" D "progenitor" NT pre-nova pre-supernova RT nova supernova ## promethium promethium ALT "Pm" D "promethium (atomic number 61)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## prominence prominence ALT "chromospheric eruption" D "prominence" NT active_prominence quiescent_prominence RT Hanle_effect Sun chromosphere flare optical_flare solar_activity solar_filament sunspot ## propagation propagation D "propagation" N "combine with other terms" ## proper_motion proper_motion D "proper motion" BT motion space_motion RT Galactic_rotation kinematics Local_Standard_of_Rest moving_cluster_parallax peculiar_motion photographic_astrometry radial_velocity radiant_moving_cluster secular_parallax stellar_dynamics stellar_motion transverse_velocity ## property property D "property" NT magnetic_property mechanical_property optical_property surface_property thermal_property N "combine with other terms" ## proportional_counter proportional_counter D "proportional counter" BT measuring_instrument NT position_sensitive_proportional_counter RT X-ray_detector CN "FVH: added NT POSITION_SENSITIVE_PROPORTIONAL_COUNTERS (2007-SEP-21)" ## protactinium protactinium ALT "Pa" D "protactinium (atomic number 91)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## protocluster protocluster D "protocluster" BT cluster RT collapsing_cloud cosmogony cosmology galaxy_cluster star_cluster ## protogalaxy protogalaxy D "protogalaxy" BT galaxy gaseous_sphere RT collapsing_cloud cosmogony cosmology ## proton-proton_reaction proton-proton_reaction ALT "proton proton cycle" "proton proton reaction" "proton-proton cycle" D "proton-proton reaction" BT hydrogen_burning RT carbon_nitrogen_cycle nuclear_fusion stellar_interior ## proton proton D "proton" BT elementary_particle fundamental_particle particle RT alpha_particle antiproton nucleus_atom ## protoplanetary_nebula protoplanetary_nebula ALT "proplyds" D "protoplanetary nebula" BT collapsing_cloud RT cosmogony protoplanet solar_nebula CN "FVH: added ALT proplyd (2007-SEP-21)" ## protoplanet protoplanet D "protoplanet" RT Solar_System planetesimal planet protoplanetary_nebula satellite solar_nebula ## protostar protostar D "protostar" BT gaseous_sphere pre-main_sequence_star RT Bok_globule Herbig-Haro_object T_Tauri_star birth_rate collapsing_cloud cometary_globule star_formation stellar_evolution ## pulsar pulsar D "pulsar" BT collapsed_star degenerate_star evolved_star radio_source relativistic_star NT X-ray_pulsar binary_pulsar optical_pulsar radio_pulsar RT frequency_shift glitch neutron_star precursor_pulse pulse_duration pulse_energy pulse_intensity pulse_profile pulse_structure pulse_width pulse_window rapid_oscillation supernova_remnant supernova ## pulsating_variable_star pulsating_variable_star D "pulsating variable star" BT intrinsic_variable_star variable_star NT 53_Persei_star BL_Herculis_star Cepheid Mira_variable_star RR_Lyrae_star RV_Tauri_star S_Vulpeculae_star SX_Phoenicis_star W_Virginis_star ZZ_Ceti_star beta_Cephei_star delta_delphini_star delta_Scuti_star double-mode_Cepheid double-mode_variable_star dwarf_Cepheid irregular_variable_star lambda_eridani_star long_period_variable_star multi-periodic_variable_star periodic_variable_star semi-regular_variable_star RT He_II_ionization_zone asteroseismology double-mode_pulsation kappa_mechanism multi-periodic_pulsation non-radial_pulsation overtone_mode period period_change period-color_relation period-density_relation period-luminosity-color_relation period-luminosity_relation period-mass_relation period-radius_relation period-spectrum_relation pulsation_mode pulsation_theory ## pulsation_mode pulsation_mode D "pulsation mode" NT fundamental_mode overtone_mode RT multi-periodic_pulsation multi-periodic_variable_star non-radial_pulsation period pulsating_variable_star pulsation_theory pulsation ## pulsation pulsation D "pulsation" RT amplitude asteroseismology pulsation_mode N "combine with other terms" ## pulsation_theory pulsation_theory D "pulsation theory" RT He_II_ionization_zone pulsating_variable_star pulsation_mode ## pulse_counter pulse_counter D "pulse counter" RT amplifier pulse ## pulse_counting pulse_counting D "pulse counting" RT amplifier pulse ## pulse_duration pulse_duration D "pulse duration" RT pulsar pulse ## pulse_energy pulse_energy D "pulse energy" RT pulsar pulse ## pulse_intensity pulse_intensity D "pulse intensity" RT pulsar pulse ## pulse_profile pulse_profile D "pulse profile" RT pulsar pulse ## pulse pulse D "pulse" RT pulse_counter pulse_counting pulse_duration pulse_energy pulse_intensity pulse_profile pulse_structure pulse_width pulse_window N "combine with other terms" ## pulse_structure pulse_structure D "pulse structure" RT pulsar pulse ## pulse_width pulse_width D "pulse width" RT pulsar pulse ## pulse_window pulse_window D "pulse window" RT pulsar pulse ## Purkinje_effect Purkinje_effect D "Purkinje effect" RT photometry variable_star visual_magnitude visual_observation ## q_branch q_branch D "q-branch" RT molecular_spectrum vibrational_spectrum ## Q_magnitude Q_magnitude D "Q magnitude" BT apparent_magnitude RT far_infrared_radiation infrared_photometry ## quadrant_detector quadrant_detector D "quadrant detector" RT autoguider control_system guide_system photomultiplier_tube ## quadrant quadrant D "quadrant" BT astrometric_instrument instrument RT meridian_circle ## quadrature quadrature D "quadrature" RT conjunction opposition ## quanta quanta ALT "quantum" D "quanta" RT photon quantum_theory ## quantization quantization ALT "quantisation UK" D "quantization" RT analysis determination measurement ## quantum_cosmology quantum_cosmology D "quantum cosmology" BT cosmology RT naked_singularity space-time_singularity ## quantum_efficiency quantum_efficiency ALT "Q.E." "QE" D "quantum efficiency" RT cathode charge-coupled_device detector image_tube photographic_emulsion photomultiplier_tube ## quantum_field_theory quantum_field_theory D "quantum field theory" RT electromagnetic_field gravitational_field quantum_theory ## quantum_mechanics quantum_mechanics D "quantum mechanics" RT Fermi-Dirac_statistics quantum_theory relativistic_velocity superconducting_tunnel_junction ## quantum_theory quantum_theory D "quantum theory" RT quanta quantum_field_theory quantum_mechanics ## quark quark D "quark" BT elementary_particle RT baryon lepton meson neutron_star ## quarter_wave_plate quarter_wave_plate D "quarter-wave plate" RT circular_polarization half-wave_plate HN "FVH: new (2007-SEP-21)" ## quasar_galaxy_pair quasar_galaxy_pair D "quasar-galaxy pair" RT galaxy quasar ## quasar_microlensing quasar_microlensing D "microlensing of AGN nucleus" BT gravitational_microlensing RT quasar HN "FVH: new (2007-OCT-8)" ## quasar quasar ALT "QSO" "quasi-stellar galaxy" "quasi-stellar object" "quasi-stellar radio_source" D "quasar" BT extragalactic_object extragalactic_radio_source NT X-ray_quasar radio_quiet_quasar RT BL_Lacertae_object Lyman_alpha_forest X-ray_source absorption_line_system active_galactic_nucleus blazar compact_galaxy double_quasar liner_galaxy luminous_arc quasar_galaxy_pair quasar_microlensing variable_source ## quiescent_prominence quiescent_prominence D "quiescent prominence" BT prominence RT Sun chromosphere ## quiet_Sun quiet_Sun D "quiet Sun" RT active_Sun solar_cycle ## radar_astronomy radar_astronomy D "radar astronomy" BT radio_astronomy RT radar radar_equipment radar_telescope radio_observatory ## radar_equipment radar_equipment D "radar equipment" NT antenna RT radar_astronomy radio_telescope ## radar_mapping radar_mapping D "radar mapping" RT map ## radar radar D "radar" NT optical_radar RT Doppler_effect antenna radar_astronomy ## radar_telescope radar_telescope D "radar telescope" BT radio_telescope RT dish_antenna parabolic_reflector radar_astronomy ## radial_pulsation radial_pulsation D "radial pulsation" RT BL_Herculis_star Cepheid He_II_ionization_zone Mira_variable_star RV_Tauri_star beta_Cephei_star delta_Scuti_star ## radial_velocity radial_velocity D "radial velocity" BT space_motion velocity NT iodine_cell RT Doppler_effect kinematics line_shift peculiar_motion peculiar_velocity proper_motion redshift spectroscopy stellar_dynamics stellar_motion tangential_velocity transverse_velocity virial_theorem ## radiant_meteor radiant_meteor D "radiant [meteor]" RT meteor_shower meteor_stream meteor_trail meteor ## radiant_moving_cluster radiant_moving_cluster D "radiant [moving cluster]" RT moving_cluster_parallax open_star_cluster proper_motion ## radiation_belt radiation_belt D "radiation belt" NT van_Allen_radiation_belt RT Earth atmosphere plasma ## radiation_damping radiation_damping D "radiation damping" RT damping_constant decay_oscillation radiative_braking ## radiation_field radiation_field D "radiation field" RT electromagnetic_field ## radiation_mechanism radiation_mechanism D "radiation mechanism" NT free-bound_emission free-free_emission RT Cerenkov_radiation Rayleigh_limit bremsstrahlung cyclotron_radiation gravitational_radiation non-LTE_transfer relativistic_particle relativistic_plasma synchrotron_radiation ## radiation_pressure radiation_pressure D "radiation pressure" RT Eddington_limit Poynting-Robertson_effect photon pressure solar_wind stellar_wind ## radiation radiation D "radiation" NT Cerenkov_radiation X-ray_radiation background_radiation continuum_radiation cosmic_ray cyclotron_radiation electromagnetic_radiation gamma-ray_radiation gravitational_radiation high-energy_radiation infrared_radiation polarized_radiation synchrotron_radiation thermal_radiation ultraviolet_radiation RT Planck_black_body_formula absorption albedo bolometer effective_temperature emissivity energy-transfer flux_density illumination irradiance opacity photon radiative_equilibrium recombination_line solar_constant CN "FVH: moved lots of NT's to electromagnetic_radiation (2007-OCT-8)" N "combine with other terms" ## radiation_scattering radiation_scattering ALT "electromagnetic wave scattering" D "radiation scattering" NT Compton_scattering Rayleigh_scattering Thomson_scattering X-ray_scattering light_scattering RT Compton_effect Raman_effect electrostatic_wave elementary_particle_scattering light_polarization phase_function photon scattering zodiacal_light ## radiative_braking radiative_braking D "radiative braking" RT damping_constant dynamical_friction radiation_damping rotating_star ## radiative_equilibrium radiative_equilibrium D "radiative equilibrium" RT absorption electromagnetic_radiation radiation temperature ## radiative_recombination radiative_recombination ALT "radiative capture" D "radiative recombination" RT airglow electron photon plasma ## radiative_transfer radiative_transfer D "radiative transfer" BT energy-transfer RT Rayleigh_limit opacity transport_process ## radical radical D "radical" BT composite_particle NT hydroxyl_radical RT ion ## radio_absorption radio_absorption D "radio absorption" RT H_I_region interstellar_matter ionosphere ## radioactive_decay radioactive_decay D "radioactive decay" RT radioactivity ## radioactivity radioactivity D "radioactivity" RT alpha_particle electron gamma-ray_radiation nuclear_fission positron radioactive_decay ## radio_antenna radio_antenna ALT "radio antennas" D "radio antennas" BT antenna RT polar_diagram radio_telescope sidelobe ## radio_astrometry radio_astrometry D "radio astrometry" BT astrometry observing_technique radio_astronomy RT interferometry long_baseline_interferometry very_long_baseline_interferometry ## radio_astronomy radio_astronomy D "radio astronomy" NT millimeter_astronomy radar_astronomy radio_astrometry submillimeter_astronomy RT clean_method N "use as nts all terms associated with radio astronomy" ## radio_background radio_background ALT "radio frequency interference" "radio noise" D "radio background" BT background_radiation RT X-ray_background cosmic_noise gamma-ray_background microwave_background radio_interference radio_radiation ultraviolet_background ## radio_burst radio_burst D "radio burst" BT burst RT X-ray_burst burster gamma-ray_burst optical_burst ## radio_core radio_core D "radio core" RT radio_source ## radio_emission radio_emission D "radio emission" BT emission_spectrum N "see radio radiation" ## radio_flare radio_flare D "radio flare" BT flare RT flare_star ## radio_frequency radio_frequency D "radio frequency" RT 21-cm_line Paul_trap radio_radiation radio_spectrum spectral_index ## radio_galaxy radio_galaxy D "radio galaxy" BT extragalactic_radio_source galaxy NT Ep_galaxy giant_radio_galaxy head_tail_galaxy RT Fanaroff-Riley_class X-ray_source active_galactic_nucleus ## radioheliograph radioheliograph D "radioheliograph" BT radio_telescope solar_telescope ## radio_interference radio_interference ALT "radio frequency interference" "radio noise" D "radio interference" NT cosmic_noise RT radio_background ## radio_interferometer radio_interferometer D "radio interferometer" BT interferometer radio_telescope NT long_baseline_interferometer t_array very_long_baseline_interferometer y_array RT array pencil_beam phased_array radio_interferometry radio_observatory ## radio_interferometry radio_interferometry D "radio interferometry" BT interferometry observing_technique NT long_baseline_interferometry very_long_baseline_interferometry RT interference_wave radio_interferometer time_synchronization N "see radio interferometer" ## radio_jet radio_jet D "radio jet" BT jet RT radio_source ## radiometer radiometer D "radiometer" BT detector measuring_instrument NT Dicke_radiometer RT bolometer photometer radiometry ## radiometry radiometry D "radiometry" RT radiometer ## radio_observatory radio_observatory D "radio observatory" BT observatory RT millimeter_astronomy radar_astronomy radio_interferometer radio_telescope submillimeter_astronomy ## radio_occultation radio_occultation D "radio occultation" BT occultation ## radio_pulsar radio_pulsar D "radio pulsar" BT pulsar RT optical_pulsar ## radio_quiet_quasar radio_quiet_quasar D "radio quiet quasar" BT quasar ## radio_radiation radio_radiation ALT "radio wave" D "radio radiation" BT electromagnetic_radiation RT Jansky radio_background radio_frequency radio_source CN "FVH: moved BT radiation to BT electromagnetic_radiation and radio_wave to ALT (2007-OCT-8)" N "synonym: radio emission" ## radio_recombination_line radio_recombination_line D "radio recombination line" BT recombination_line NT 21-cm_line RT H_I_region H_II_region maser ## radio_source_catalog radio_source_catalog D "radio source catalog" BT catalog RT radio_source_count N "combine with other terms" ## radio_source_count radio_source_count D "radio source count" RT observational_cosmology radio_source_catalog radio_source statistics survey ## radio_source radio_source D "radio source" BT source NT OH_source compact_source discrete_radio_source extended_source extragalactic_radio_source head_tail_galaxy pulsar radio_star variable_source RT SiO_maser bipolar_outflow galaxy_encounter interplanetary_scintillation interstellar_scintillation ionospheric_scintillation jet lobe maser optical_identification radio_core radio_jet radio_radiation radio_source_count supernova_remnant N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## radio_spectrum radio_spectrum D "radio spectrum" BT spectrum RT microwave_spectrum radio_frequency radio_spectrograph radio_spectroscopy spectral_index ## radio_spectrograph radio_spectrograph ALT "radio spectrometer" D "radio spectrograph" BT spectrograph RT radio_spectrum radio_spectroscopy ## radio_spectroscopy radio_spectroscopy D "radio spectroscopy" RT radio_spectrum radio_spectrograph ## radio_star radio_star D "radio star" BT radio_source NT flare_star RT X-ray_star ## radio_structure radio_structure D "radio structure" NT lobe RT bipolar_outflow compact_source contour_map drift_scan extended_source head_tail_galaxy ## radio_telescope radio_telescope D "radio telescope" BT telescope NT Cassegrain_antenna Mills_cross_antenna Yagi_antenna dish_antenna radar_telescope radio_interferometer radioheliograph very_long_baseline_interferometer RT antenna_design antenna apodization array beam_switching beamwidth feed_horn half-wave_dipole interferometer parabolic_reflector phase_rotator phase_switching radar_equipment radio_antenna radio_observatory receiver shaped_reflector subreflector N "not a complete list of terms" ## radio_transmission_window radio_transmission_window D "radio transmission window through the atmosphere" BT atmospheric_window RT infrared_transmission_window interstellar_matter optical_transmission_window CN "FVH: renamed to avoid confusion with optics (2007-NOV-2)" N "low absorption in atmosphere" ## radio_waveguide radio_waveguide D "radio waveguide" BT waveguide NT horn_antenna ## radium radium ALT "Ra" D "radium (atomic number 88)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## radius-luminosity_relation radius-luminosity_relation ALT "radius luminosity relation" D "radius-luminosity relation" BT statistical_relation NT fundamental_plane RT Cepheid period-color_relation period-density_relation period-luminosity-color_relation period-luminosity_relation period-mass_relation period-radius_relation period-spectrum_relation ## radon radon ALT "Rn" D "radon (atomic number 86)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## RAID_array RAID_array D "RAID array of hard disk" BT data_storage HN "FVH: new (2007-NOV-2)" ## Raman_effect Raman_effect D "Raman effect" RT Raman_scattering Raman_spectrum Raman_spectroscopy absorption_spectrum emission_spectrum radiation_scattering ## Raman_scattering Raman_scattering D "Raman scattering" RT Raman_effect N "see Raman effect" ## Raman_spectrum Raman_spectrum D "Raman spectrum" RT Raman_effect light_scattering N "see Raman effect" ## Raman_spectroscopy Raman_spectroscopy D "Raman spectroscopy" BT spectroscopy RT Raman_effect molecular_spectrum N "see Raman effect" ## Ramsden_eyepiece Ramsden_eyepiece D "Ramsden eyepiece" BT eyepiece ## range_finder range_finder D "range finder" BT measuring_instrument RT distance ## Rankine-Hugoniot_relation Rankine-Hugoniot_relation D "Rankine-Hugoniot relation" RT density pressure shock_wave ## rapid_burst rapid_burst D "rapid burst" BT burst RT X-ray_burst gamma-ray_burst ## rapid_oscillation rapid_oscillation D "rapid oscillation" RT Ap_star asteroseismology pulsar ## rare_earth rare_earth D "rare earth" BT fundamental_chemical_element NT cerium dysprosium erbium europium gadolinium holmium lanthanum lutetium neodymium praseodymium samarium scandium terbium thulium ytterbium yttrium RT abundance metal_abundance metal_line ## R_association R_association ALT "R-association" D "R association" BT star_association RT reflection_nebula young_star ## ratio ratio D "ratio" NT axial_ratio HN "ES: new (2007-OCT-11)" ## Rayleigh Rayleigh D "Rayleigh" RT aurora night_sky_brightness N "solar aurora flux unit" ## Rayleigh_criterion Rayleigh_criterion ALT "Rayleigh limit" D "Rayleigh criterion" RT diffraction resolution ## Rayleigh_limit Rayleigh_limit D "Rayleigh limit" RT radiation_mechanism radiative_transfer N "refers to radiation mechanism" ## Rayleigh_number Rayleigh_number D "Rayleigh number" RT convection thermal_stability ## Rayleigh_scattering Rayleigh_scattering D "Rayleigh scattering" BT light_scattering radiation_scattering RT Compton_scattering Mie_scattering Thomson_scattering airglow interstellar_absorption night_sky_brightness ## Rayleigh-Taylor_instability Rayleigh-Taylor_instability D "Rayleigh-Taylor instability" BT instability RT fluid_mechanics ## ray ray D "lunar ray" RT Moon N "refers to lunar feature" ## Razin_effect Razin_effect D "Razin effect" RT synchrotron_radiation N "also Razin-Tsytovich effect" ## R_Canis_Majoris_star R_Canis_Majoris_star ALT "R CMa star" D "R Canis Majoris star" BT eclipsing_binary_star ## R_Coronae_Borealis_star R_Coronae_Borealis_star ALT "R Cor Bor star" "RCB star" D "R Coronae Borealis star" BT irregular_variable_star RT circumstellar_dust circumstellar_grain supergiant ## read_out_noise read_out_noise ALT "RON" D "read-out noise" BT noise RT charge-coupled_device HN "FVH: new (2007-SEP-21)" ## real_anomaly real_anomaly D "real anomaly" BT orbital_anomaly ## receiver receiver D "receiver" RT correlation detector interferometric_correlation phase_sensitive_detector phase_switching radio_telescope ## recombination_line recombination_line D "recombination line" BT emission_line NT radio_recombination_line RT electromagnetic_radiation radiation recombination spectrum ## recombination recombination D "recombination" RT electron photoionization recombination_line ## recurrent_nova recurrent_nova D "recurrent nova" BT nova RT fast_nova slow_nova ## reddened_star reddened_star D "reddened star" RT absorption interstellar_absorption interstellar_reddening reddening reddening_law ## reddening_law reddening_law D "reddening law" RT gas_to_dust_ratio interstellar_reddening reddened_star selective_absorption ## reddening reddening D "reddening" NT interstellar_reddening RT absorption intergalactic_absorption interstellar_absorption interstellar_dust interstellar_gas intrinsic_color reddened_star selective_absorption ## red_dwarf_flare_star red_dwarf_flare_star D "red dwarf flare star" BT flare_star late-type_dwarf ## red_dwarf red_dwarf D "red dwarf star" N "see late-type dwarf star" ## red_giant_bump red_giant_bump ALT "red bump" D "red giant bump" BT giant_branch RT metal-rich_star HN "ES: new (2007-OCT-8)" ## red_giant_clump red_giant_clump ALT "red clump" D "red giant clump" BT giant_branch HN "ES: new (2007-OCT-8)" ## red_giant red_giant D "red giant star" N "see late-type giant star" ## red_giant_tip red_giant_tip D "red giant tip" BT giant_branch RT Hertzsprung-Russell_diagram RGB_tip_distance carbon_flash evolved_star helium_flash late-type_giant ## redshift_distance_relation redshift_distance_relation D "redshift-distance relation" RT Dark_Energy cosmological_distance_scale cosmology observational_cosmology ## redshift_magnitude_relation redshift_magnitude_relation D "redshift-magnitude relation" RT Dark_Energy Hubble_constant Hubble_diagram Hubble_law cosmological_distance_scale cosmology ## redshift redshift ALT "red shift" D "redshift" BT Doppler_effect line_shift NT gravitational_redshift RT Hubble_diagram Hubble_law Lyman_alpha_forest Tully-Fisher_relation cosmological_distance_scale cosmology frequency_shift k_correction observational_cosmology radial_velocity ## red_star red_star D "red star" N "see either late-type star or reddened star" ## red_supergiant red_supergiant D "red supergiant star" N "see late-type supergiant star" ## reduction_method reduction_method D "reduction method" RT analysis astronomical_technique data_processing data_reduction ## reference_frame reference_frame D "reference frame" RT coordinate_system ## reference_system reference_system D "reference system" RT astrometry coordinate_system position spherical_coordinate ## reflecting_telescope reflecting_telescope ALT "reflector" D "reflecting telescope" BT optical_telescope NT Baker-Nunn_camera Bouwers_telescope Maksutov_telescope Ritchey-Chretien_telescope Schmidt_telescope coelostat multiple_mirror_telescope wide-field_telescope RT parabolic_reflector primary_mirror secondary_mirror tertiary_mirror N "refers to optical telescope" ## reflection_grating reflection_grating D "reflection grating" BT diffraction_grating RT echelle_grating objective_grating transmission_grating ## reflection_nebula reflection_nebula D "reflection nebula" BT interstellar_matter nebula RT R_association ## reflection reflection D "reflection" RT albedo mirror refraction scattering thin_film transmission ## reflector_antenna reflector_antenna ALT "reflector antennas" D "reflector antenna" BT antenna ## refracting_telescope refracting_telescope D "refracting telescope" BT optical_telescope NT zenith_telescope RT primary_lens ## refraction_angle refraction_angle ALT "angle of refraction" D "angle of refraction" RT atmosphere zenith_distance N "in Earth's atmosphere" ## refraction refraction D "refraction" RT electromagnetic_radiation lens reflection refractive_index scattering transmission visible_radiation wave_propagation ## refractive_index refractive_index D "refractive index" BT optical_property RT atmospheric_refraction lens optical_pathlength optics refraction ## regression_of_node regression_of_node D "regression of node" RT Moon orbital_element ## relativistic_astrophysics relativistic_astrophysics D "relativistic astrophysics" RT black_hole cosmology gravity neutron_star relativistic_cosmology ## relativistic_cosmology relativistic_cosmology D "relativistic cosmology" BT cosmology RT relativistic_astrophysics ## relativistic_disk relativistic_disk D "relativistic discs" UK "relativistic disk" RT relativistic_effect relativistic_electron relativistic_plasma relativity ## relativistic_effect relativistic_effect D "relativistic effect" RT relativistic_disk relativistic_electron relativistic_plasma relativity ## relativistic_electron relativistic_electron D "relativistic electron" BT electron_beam relativistic_particle RT relativistic_disk relativistic_effect synchrotron_radiation ## relativistic_fluid_dynamics relativistic_fluid_dynamics D "relativistic fluid dynamics" BT fluid_dynamics relativistic_mechanics ## relativistic_mechanics relativistic_mechanics D "relativistic mechanics" NT relativistic_fluid_dynamics RT relativity ## relativistic_particle relativistic_particle D "relativistic particle" BT particle NT relativistic_electron RT radiation_mechanism ## relativistic_plasma relativistic_plasma ALT "relativistic gas" D "relativistic plasma" BT gas plasma RT radiation_mechanism relativistic_disk relativistic_effect relativity ## relativistic_star relativistic_star D "relativistic star" NT black_hole neutron_star pulsar RT X-ray_source relativity ## relativistic_velocity relativistic_velocity D "relativistic velocity" BT velocity RT Big_Bang_theory cosmology quantum_mechanics relativity ## relativity relativity D "relativity" BT cosmogony NT general_theory_of_relativity RT field_equation gravitation inertial_coordinate_system inertial_reference_frame relativistic_disk relativistic_effect relativistic_mechanics relativistic_plasma relativistic_star relativistic_velocity ## relaxation_time relaxation_time D "relaxation time" RT age galaxy_cluster star_cluster stellar_dynamics ## remote_control_system remote_control_system D "remote control system" BT control_system RT automated_telescope automatic_patrol_telescope telescope_instrument telescope ## remote_sensing remote_sensing D "remote sensing" RT detector infrared_radiation microwave_radiation ## research research D "research" RT design discoveries observation theory ## reseaux reseaux D "reseaux" RT calibration grid photographic_plate spectroscopy ## residual_intensity residual_intensity D "residual intensity" RT absorption_line line_profile ## resolution resolution D "resolution" NT angular_resolution spectral_resolution RT Rayleigh_criterion interferometry optics pixel sensitivity sidelobe visual_acuity ## resonance_gap resonance_gap D "resonance gap" NT Kirkwood_gap RT asteroid planetary_ring planet shepherd_satellite ## resonance_line resonance_line D "resonance line" NT H_alpha Lyman_alpha RT spectrum N "not a complete list of terms" ## retardation retardation D "retardation" N "combine with other terms" ## reticle reticle D "reticle" RT eyepiece graticule grid ## reticon_array reticon_array D "reticon array" BT multi-channel_detector RT diode_array ## rgb_photometry rgb_photometry ALT "red-green-blue photometry" D "rgb photometry" BT broad_band_photometry photometric_system HN "FVH: new (2007-SEP-21)" ## RGB_tip_distance RGB_tip_distance D "distance obtained from the tip of the red giant branch" BT distance_measurement RT red_giant_tip HN "ES: new (2007-OCT-8)" ## rgu_photometry rgu_photometry D "rgu photometry" BT broad_band_photometry ## rhenium rhenium ALT "Re" D "rhenium (atomic number 75)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## rho_Cassiopeiae_star rho_Cassiopeiae_star ALT "rho Cas star" D "rho Cassiopeiae star" ## rhodium rhodium ALT "Rh" D "rhodium (atomic number 45)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Right_Ascension Right_Ascension ALT "celestial longitude" D "Right Ascension" BT equatorial_coordinate_system longitude RT Declination celestial_equator equator hour_angle transit_time ## rigid_body_rotation rigid_body_rotation D "rigid body rotation" BT rotation RT rotating_body ## rill rill D "rill" RT planet satellite ## ring_division ring_division D "ring division" RT planetary_ring planet ## ring_galaxy ring_galaxy D "ring galaxy" BT galaxy peculiar_galaxy RT ring ## ring_nebula ring_nebula D "ring nebula" BT nebula RT planetary_nebula ## ring ring D "ring" NT planetary_ring stellar_ring RT ansa ring_galaxy ## Ritchey-Chretien_telescope Ritchey-Chretien_telescope ALT "RC" D "Ritchey-Chretien telescope" BT reflecting_telescope ## R_magnitude R_magnitude D "R magnitude" BT apparent_magnitude RT Bessel_photometry Johnson_photometry Kron-Cousins_photometry ## Roche_limit Roche_limit D "Roche limit" RT close_binary_star gravitation orbit planetary_ring planet tidal_disruption ## Roche_lobe Roche_lobe D "Roche lobe" RT close_binary_star eclipsing_binary_star interacting_binary_star tidal_interaction ## rocket-borne_instrument rocket-borne_instrument ALT "rocket borne instrument" D "rocket-borne instrument" RT X-ray_astronomy airplane-borne_instrument balloon-borne_instrument cosmic_ray_astronomy gamma-ray_astronomy ground-based_astronomy infrared_observatory satellite-borne_instrument space_probe_instrument space_telescope ultraviolet_astronomy ## roentgenium roentgenium ALT "Rg" D "roentgenium (atomic number 111)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Rosseland_opacity Rosseland_opacity D "Rosseland opacity" BT opacity RT Kramers_opacity absorption stellar_interior ## rotating_body rotating_body D "rotating body" NT asteroid circumstellar_disk comet dwarf_planet galaxy planet rotating_star RT rigid_body_rotation rotation ## rotating_shell rotating_shell D "rotating shell" BT circumstellar_shell ## rotating_star rotating_star D "rotating star" BT rotating_body NT periodic_variable_star RT radiative_braking synchronous_rotation von_Zeipel_theorem ## rotational_velocity rotational_velocity D "rotational velocity" BT velocity RT rotation tangential_velocity HN "ES: new (2007-OCT-11)" ## rotation rotation D "rotation" NT Earth_rotation Galactic_rotation differential_rotation galaxy_rotation_curve rigid_body_rotation synchronous_rotation RT angular_momentum angular_velocity equatorial_bulge oblateness period rotating_body rotational_velocity N "combine with other terms" ## r-process r-process ALT "r process" D "r-process" RT nucleosynthesis p_process s-process supernova ## RRab_star RRab_star D "RRab star" BT RR_Lyrae_star ## RRa_star RRa_star D "RRa star" BT RR_Lyrae_star ## RRb_star RRb_star D "RRb star" BT RR_Lyrae_star ## RRc_star RRc_star D "RRc star" BT RR_Lyrae_star ## RR_Lyrae_star RR_Lyrae_star ALT "cluster type variable star" D "RR Lyrae star" BT double-mode_variable_star population_II_Cepheid pulsating_variable_star NT Bailey_type RRa_star RRab_star RRb_star RRc_star RT BL_Herculis_star Blazhko_effect Cepheid Galactic_halo Oosterhoff_group W_Virginis_star globular_star_cluster horizontal_branch_star ## RR_Telescopii_star RR_Telescopii_star D "RR Telescopii star" ## RS_Canum_Venaticorum_star RS_Canum_Venaticorum_star D "RS Canum Venaticorum star" BT X-ray_source binary_star multi-periodic_variable_star RT starspot ## R_star R_star D "R star" BT giant late-type_star RT carbon_star spectral_type ## rubidium rubidium ALT "Rb" D "rubidium (atomic number 37)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## runaway_star runaway_star D "runaway star" RT OB_star binary_star high-velocity_star supernova ## ruthenium ruthenium ALT "Ru" D "ruthenium (atomic number 44)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## rutherfordium rutherfordium ALT "Rf" D "rutherfordium (atomic number 104)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## RV_Tauri_star RV_Tauri_star D "RV Tauri star" BT emission_line_star irregular_variable_star late-type_supergiant long_period_variable_star pulsating_variable_star semi-regular_variable_star RT S_Vulpeculae_star radial_pulsation ## RW_Aurigae_star RW_Aurigae_star D "RW Aurigae star" BT emission_line_star irregular_variable_star pre-main_sequence_star ultraviolet_excess_star RT H_alpha_emission_line_star T_association T_Tauri_star ## Saha_equation Saha_equation D "Saha equation" RT ion thermal_equilibrium ## samarium samarium ALT "Sm" D "samarium (atomic number 62)" BT fundamental_chemical_element rare_earth HN "FVH: new (2007-OCT-25)" ## sampling sampling D "sampling" N "combine with other terms" ## Saros_cycle Saros_cycle D "Saros cycle" RT lunar_eclipse lunar_phase metonic_cycle ## satellite-borne_instrument satellite-borne_instrument ALT "satellite borne instrument" D "satellite-borne instrument" RT X-ray_astronomy airplane-borne_instrument balloon-borne_instrument cosmic_ray_astronomy gamma-ray_astronomy ground-based_astronomy infrared_astronomy millimeter_astronomy rocket-borne_instrument space_probe_instrument space_telescope ultraviolet_astronomy ## satellite_laser_ranging satellite_laser_ranging D "satellite laser ranging" BT laser_ranging RT artificial_satellite laser lunar_laser_ranging optical_radar ## satellite satellite D "satellite" NT Moon galilean_satellite planet_satellite RT Solar_System global_positioning_system planetesimal planet protoplanet rill surface_of_celestial_body topography volcano N "natural satellite; see artifical_satellite" ## Saturn Saturn D "Saturn" BT Jovian_planet planet RT Solar_System HN "FVH: new (2007-SEP-24)" ## SBF_distance SBF_distance ALT "SBF" D "surface brightness fluctuation distance" BT distance_measurement RT elliptical_galaxy HN "ES: new (2007-OCT-8)" ## scale_height scale_height D "scale height" RT Earth_atmosphere atmosphere atmospheric_density stellar_atmosphere ## scandium scandium ALT "Sc" D "scandium (atomic number 21)" BT fundamental_chemical_element rare_earth HN "FVH: new (2007-OCT-25)" ## scattering scattering D "scattering" NT Compton_scattering Mie_scattering atmospheric_extinction elementary_particle_scattering gamma-ray_scattering light_scattering RT radiation_scattering reflection refraction ## Schmidt_camera Schmidt_camera D "Schmidt camera" BT camera photographic_instrument RT Schmidt_telescope corrector_plate ## Schmidt_telescope Schmidt_telescope D "Schmidt telescope" BT catadioptric_system photographic_instrument reflecting_telescope RT Baker-Nunn_camera Maksutov_telescope Schmidt_camera corrector_plate objective_prism wide-field_telescope ## Schwarzschild_metric Schwarzschild_metric D "Schwarzschild metric" RT general_theory_of_relativity gravitational_field ionization orbit space-time_singularity ## Schwarzschild_radius Schwarzschild_radius D "Schwarzschild radius" RT black_hole general_theory_of_relativity N "limiting radius of black hole" ## scientific_field scientific_field D "scientific and related field" NT Earth_sciences aeronomy astrobiology astrology astronomy astrophysics atomic_physics biology celestial_mechanics chemistry engineering fluid_mechanics mathematics ## scintillation_counter scintillation_counter D "scintillation counter" BT counter NT Cerenkov_counter RT image_tube phosphorescence phosphorescent_scintillation photomultiplier_tube ## scintillation scintillation D "scintillation" NT atmospheric_scintillation interplanetary_scintillation interstellar_scintillation ionospheric_scintillation phosphorescent_scintillation RT Earth Earth_atmosphere atmosphere atmospheric_refraction speckle turbulence_Earth_atmosphere ## S_Doradus_star S_Doradus_star ALT "P Cygni star" D "S Doradus star" BT early-type_variable_star emission_line_star shell_star RT P_Cygni_line_profile ## seaborgium seaborgium ALT "Sg" D "seaborgium (atomic number 106)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## search_for_extraterrestrial_life search_for_extraterrestrial_life ALT "SETI" D "search for extraterrestrial life" RT extraterrestrial_intelligence extraterrestrial_life CN "FVH: added RT EXTRATERRESTRIAL_INTELLIGENCE (2007-OCT-1)" "FVH: explicit wording of token; SETI to ALT (2007-OCT-4)" ## seasonal_phenomena seasonal_phenomena D "seasonal phenomena" N "combine with other terms" ## season season D "season" N "combine with other terms" ## secondary_cosmic_ray secondary_cosmic_ray D "secondary cosmic ray" RT cosmic_ray_shower cosmic_ray ## secondary_mirror secondary_mirror D "secondary mirror" BT telescope_mirror RT Cassegrain_antenna Cassegrain_focus optical_telescope primary_mirror reflecting_telescope subreflector tertiary_mirror ## secondary_star secondary_star D "secondary star" BT companion_star RT primary_star tertiary_star HN "ES: new (2007-OCT-8)" ## secular_parallax secular_parallax D "secular parallax" BT parallax RT moving_cluster_parallax proper_motion star_association ## seeing_monitor seeing_monitor D "seeing monitor" BT optical_instrument NT differential_image_motion_monitor RT optical_observatory seeing site_testing ## seeing seeing D "seeing" NT dome_seeing RT Earth_atmosphere active_optics adaptive_optics atmospheric_refraction atmospheric_scintillation point_spread_function seeing_monitor site_testing speckle_interferometry speckle tip-tilt_mirror turbulence_Earth_atmosphere ## segmented_optics segmented_optics D "segmented optics" RT adaptive_optics multiple_mirror_telescope tip-tilt_mirror very_large_telescope ## seismology seismology D "seismology" NT asteroseismology helioseismology RT Earth stellar_oscillation vibration ## selection_effect selection_effect D "selection effect" BT error RT correction statistics N "combine with other terms" ## selective_absorption selective_absorption D "selective absorption" RT gas_to_dust_ratio interstellar_matter interstellar_reddening reddening reddening_law ## selenium selenium ALT "Se" D "selenium (atomic number 34)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## selenology selenology D "selenology" RT Moon ## self-absorption self-absorption ALT "self absorption" D "self-absorption" RT spectrum ## self-calibration_method self-calibration_method ALT "self calibration method" D "self-calibration method" BT calibration ## semi-barium_star semi-barium_star ALT "semibarium star" D "semi-barium star" BT barium_star ## semiconductor_device semiconductor_device D "semiconductor device" NT charge-coupled_device charge-injection_device charge-transfer_device photovoltaic_cell RT Gunn_diode detector ## semi-detached_binary_star semi-detached_binary_star ALT "semidetached binary star" D "semi-detached binary star" BT binary_star close_binary_star RT detached_binary_star ## semimajor_axis semimajor_axis ALT "semi-major axis" D "semimajor axis" BT orbital_element NT major_axis RT binary_star planet ## semiminor_axis semiminor_axis ALT "semi-minor axis" D "semiminor axis" NT minor_axis ## semi-regular_variable_star semi-regular_variable_star ALT "semiregular variable star" D "semi-regular variable star" BT late-type_giant pulsating_variable_star variable_star NT RV_Tauri_star S_Vulpeculae_star RT Mira_variable_star irregular_variable_star supergiant ## sensitivity sensitivity D "sensitivity" RT detector integration_time limiting_magnitude polar_diagram precision resolution signal_detection signal-to-noise_ratio ## sensitometer sensitometer D "sensitometer" BT measuring_instrument ## separation separation D "separation" RT binary_star occulting_disk visual_binary_star N "combine with other terms" ## sextant sextant D "sextant" BT astrometric_instrument instrument RT altitude_angle ## Seyfert_galaxy Seyfert_galaxy D "Seyfert galaxy" BT peculiar_galaxy RT BL_Lacertae_object Markarian_galaxy Seyfert_nucleus X-ray_source compact_nucleus emission_line_galaxy liner_galaxy massive_object ## Seyfert_nucleus Seyfert_nucleus D "Seyfert nucleus" BT active_galactic_nucleus compact_nucleus emission_line_galaxy RT Seyfert_galaxy ## S_galaxy S_galaxy D "spiral galaxy (Yerkes classification scheme)" BT spiral_galaxy RT Yerkes_classification HN "FVH: new (2007-OCT-12)" ## shadow_band shadow_band D "shadow band" RT diffraction interference_wave solar_eclipse ## shaped_reflector shaped_reflector D "shaped reflector" RT radio_telescope ## shell_burning shell_burning D "shell burning" RT carbon_burning helium_burning hydrogen_burning nuclear_fusion N "nuclear fusion in shell" ## shell shell D "shell" NT circumstellar_shell convective_shell dust_shell RT shell_star ## shell_star shell_star D "shell star" NT S_Doradus_star Z_Andromedae_star gamma_Cassiopeiae_star RT P_Cygni_line_profile circumstellar_shell shell N "ES: deleted BT emission_line_star (2007-OCT-8)" ## shepherd_satellite shepherd_satellite D "shepherd satellite" RT planetary_ring resonance_gap ## shock shock D "shock" RT collisional_plasma ionization stellar_wind supernova N "combine with other terms" ## shock_wave shock_wave D "shock wave" NT bow_shock ionizing_shock_wave RT Rankine-Hugoniot_relation jump_condition sound_speed supernova_envelope velocity_field wave_propagation ## short_period_variable_star short_period_variable_star D "short period variable star" NT beta_Cephei_star delta_Scuti_star ## shot_noise shot_noise D "shot noise" BT noise RT detector electronic_equipment ## shutter shutter D "shutter" RT camera detector HN "FVH: new (2007-SEP-21)" ## sidelobe sidelobe ALT "lobe [telescope beam]" D "sidelobe" RT polar_diagram radio_antenna resolution ## sidereal_time sidereal_time ALT "S.T." D "sidereal time" BT time RT Earth civil_time equation_of_the_equinox hour_angle transit_time year ## siderostat siderostat D "siderostat" RT altazimuth_mounting coelostat drive heliostat telescope_mounting ## sigma8 sigma8 ALT "sigma_8" D "the normalization factor of the cosmological matter power spectrum" BT cosmological_parameter HN "FVH: new (2007-OCT-24)" ## signal_analysis signal_analysis D "signal analysis" BT analysis RT signal_detection signal_processing ## signal_detection signal_detection D "signal detection" BT detection RT detector limiting_magnitude sensitivity signal_analysis signal_processing ## signal_processing signal_processing D "signal processing" BT analysis RT signal_analysis signal_detection ## signal-to-noise_ratio signal-to-noise_ratio ALT "SNR" "signal to noise ratio" D "signal to noise ratio" RT background_noise integration_time limiting_magnitude noise sensitivity sky_noise ## silicon_burning silicon_burning D "silicon burning" BT nuclear_fusion nucleosynthesis RT carbon_burning helium_burning hydrogen_burning silicon ## silicon_monoxide silicon_monoxide ALT "SiO" D "SiO molecule" RT SiO_maser silicon HN "FVH: new (2007-OCT-2)" CN "FVH: explicit wording of token (2007-OCT-4)" ## silicon silicon ALT "Si" D "silicon (atomic number 14)" BT fundamental_chemical_element RT silicon_burning silicon_monoxide silicon_star HN "FVH: new (2007-OCT-25)" ## silicon_star silicon_star D "silicon star" BT Ap_star metal-rich_star RT silicon ## silver_coating silver_coating D "silver coating" BT coating thin_film RT aluminum_coating optical_surface silver ## silver silver ALT "Ag" D "silver (atomic number 47)" BT fundamental_chemical_element RT silver_coating HN "FVH: new (2007-OCT-25)" ## simulation simulation D "simulation" NT computer_simulation RT model ## singularity singularity D "singularity" NT naked_singularity space-time_singularity ## SiO_maser SiO_maser D "SiO maser" BT maser RT OH_maser interstellar_matter radio_source silicon_monoxide water_maser ## site_protection site_protection D "site protection" RT air_pollution light_pollution observatory ## site_testing site_testing D "site testing" RT observatory pollution seeing seeing_monitor sky_brightness ## sky_brightness sky_brightness D "sky brightness" NT night_sky_brightness RT Milky_Way_galaxy airglow atmospheric_radiation aurora background_radiation site_testing sunlight twilight zodiacal_light ## sky_noise sky_noise D "sky noise" BT noise RT background_noise signal-to-noise_ratio ## sky sky D "sky" N "combine with other terms" ## sky_survey sky_survey D "sky survey" BT survey RT atlas catalog finding_chart map ## slit_mask slit_mask D "slit mask" BT spectrograph_slit HN "FVH: new (2007-OCT-3)" ## Sloan_photometry Sloan_photometry ALT "SDSS photometry" D "Sloan photometry" BT broad_band_photometry photometric_system RT two-color_photometry HN "FVH: new (2007-SEP-21)" ## slow_nova slow_nova ALT "novoid" D "slow nova" BT nova NT DQ_Herculis_star RT fast_nova recurrent_nova ## Small_Magellanic_Cloud Small_Magellanic_Cloud ALT "SMC" D "Small Magellanic Cloud" BT Magellanic_cloud RT Large_Magellanic_Cloud ## sodium sodium ALT "Na" D "sodium (atomic number 11)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## soft_gamma-ray_repeater soft_gamma-ray_repeater D "soft gamma-ray repeater" BT gamma-ray_source irregular_variable_star magnetar HN "ES: new (2007-OCT-8)" ## solar_activity solar_activity D "solar activity" NT solar_storm RT Maunder_minimum active_Sun activity_index aurora butterfly_diagram coronal_loop emerging_flux ephemeral_active_region flare heliosphere magnetic_storm prominence solar_atmosphere solar_cycle solar_wind sunspot_cycle sunspot_group sunspot_number sunspot ## solar_atmosphere solar_atmosphere D "solar atmosphere" BT stellar_atmosphere RT chromosphere heliopause heliosphere limb_darkening line_formation solar_activity solar_corona solar_physics solar_storm solar_surface solar-terrestrial_relation solar_wind ## solar_constant solar_constant D "solar constant" RT Sun electromagnetic_radiation radiation solar_physics sunlight ## solar_corona solar_corona D "solar corona" BT corona NT m_region RT K_corona Sun coronagraph coronal_dimming coronal_hole coronal_line coronal_loop coronal_mass_ejection coronal_plume coronal_transient coronal_wave solar_atmosphere transition_region ## solar_cycle solar_cycle D "solar cycle" RT active_Sun butterfly_diagram quiet_Sun solar_activity solar_physics sunspot_cycle sunspot_number ## solar_day solar_day D "solar day" RT Universal_Time ephemeris_time ## solar_eclipse solar_eclipse D "solar eclipse" BT eclipse RT Moon Sun bailys_bead diamond_ring_effect flash_spectrum penumbra shadow_band umbra zone_of_totality ## solar_filament solar_filament D "solar filament" RT Sun chromosphere flare prominence sunspot ## solar_interior solar_interior D "solar interior" BT stellar_interior RT solar_neutrino_problem solar_physics stellar_evolution stellar_structure ## solar_motion solar_motion D "solar motion" BT motion RT antapex apex N "with respect to nearby star" ## solar_nebula solar_nebula D "solar nebula" RT Solar_System planet protoplanetary_nebula protoplanet ## solar_neutrino_problem solar_neutrino_problem D "solar neutrino problem" RT neutrino nuclear_reaction solar_interior ## solar_observatory solar_observatory D "solar observatory" RT coronagraph solar_optical_telescope solar_radio_telescope solar_telescope ## solar_optical_telescope solar_optical_telescope D "solar optical telescope" BT solar_telescope RT solar_observatory solar_radio_telescope ## solar_oscillation solar_oscillation ALT "five minute oscillation" D "solar oscillation" BT stellar_oscillation RT asteroseismology helioseismology ## solar_parallax solar_parallax D "solar parallax" RT Astronomical_Unit Earth_orbit ## solar_physics solar_physics D "solar physics" RT Sun forbush_effect solar_atmosphere solar_constant solar_cycle solar_interior solar_telescope solar-terrestrial_relation ## solar-planetary_relation solar-planetary_relation ALT "solar planetary relation" D "solar-planetary relation" NT solar-terrestrial_relation RT Solar_System Sun planet ## solar_radio_telescope solar_radio_telescope D "solar radio telescope" BT solar_telescope RT solar_observatory solar_optical_telescope ## solar solar D "solar" N "see under Sun" ## solar_storm solar_storm D "solar storm" BT solar_activity RT solar_atmosphere ## solar_surface solar_surface D "solar surface" RT Sun photosphere solar_atmosphere supergranulation ## Solar_System Solar_System D "Solar System" BT planetary_system RT Bodes_law Ceres Earth Earth-Moon_system Edgeworth-Kuiper_belt Jupiter Kreutz_sungrazer Mars Mercury Neptune Pluto Saturn Sun Uranus Venus asteroid comet extrasolar_planet origin planetary_alignment planetary_theory planetesimal planet pre-solar_nebula protoplanet satellite solar_nebula solar-planetary_relation synodic_period trans-Neptunian_object transplutonian_planet N "not a complete list of terms" ## solar_telescope solar_telescope ALT "tower telescope" D "solar telescope" BT telescope NT radioheliograph solar_optical_telescope solar_radio_telescope RT heliostat solar_observatory solar_physics ## solar-terrestrial_relation solar-terrestrial_relation ALT "solar terrestiral relation" D "solar-terrestrial relation" BT solar-planetary_relation RT Earth Sun solar_atmosphere solar_physics ## solar_wind solar_wind D "solar wind" BT interplanetary_matter plasma stellar_wind RT Poynting-Robertson_effect coronal_hole heliopause heliosphere interplanetary_gas interstellar_wind radiation_pressure solar_activity solar_atmosphere ## solstice solstice D "solstice" NT summer_solstice winter_solstice RT Tropic_of_Cancer Tropic_of_Capricorn ecliptic equinox ## sound_speed sound_speed ALT "speed of sound" D "speed of sound" RT acoustic_wave shock_wave ## source source D "astronomical source" NT X-ray_source compact_source cosmic_ray_source extended_source field_star gamma-ray_source gravitationally_lensed_source infrared_source non-thermal_source radio_source variable_source HN "FVH: new (2007-NOV-4)" ## South_Celestial_Pole South_Celestial_Pole D "South Celestial Pole" ALT "SCP" "S.C.P." BT celestial_pole RT North_Celestial_Pole ## South_Ecliptic_Pole South_Ecliptic_Pole D "South Ecliptic Pole" ALT "SEP" "S.E.P." BT ecliptic_pole RT North_Ecliptic_Pole ## southern_hemisphere southern_hemisphere D "southern hemisphere" RT northern_hemisphere ## South_Galactic_Pole South_Galactic_Pole D "South Galactic Pole" ALT "SGP" "S.G.P." BT Galactic_pole RT North_Galactic_Pole ## space_astrometry space_astrometry D "space astrometry" BT astrometry RT space_geodesy space_observatory ## space_astronomy space_astronomy D "space astronomy" BT astronomy NT X-ray_astronomy gamma-ray_astronomy ultraviolet_astronomy RT artificial_satellite space_observatory space_exploration space_probe ## space_biology space_biology D "space biology" BT biology space_research RT space_observatory space_vehicle ## space_debris space_debris ALT "debris" D "space debris" BT space_vehicle RT space_law space_pollution ## space_exploration space_exploration D "space exploration" RT discoveries interstellar_communication planet space_astronomy space_observatory space_probe space_research space_telescope space_vehicle ## space_geodesy space_geodesy D "space geodesy" BT geodesy RT Earth space_astrometry space_observatory ## space_law space_law D "space law" RT space_debris space_research ## space_motion space_motion D "space motion" BT motion NT proper_motion radial_velocity RT Galactic_rotation stellar_motion transverse_velocity ## space_observatory space_observatory D "space observatory" ALT "orbiting observatory" BT observatory artificial_satellite NT Hubble_Space_Telescope IRAS_satellite X-ray_observatory gamma-ray_observatory RT infrared_observatory space_astrometry space_astronomy space_biology space_exploration space_geodesy space_probe space_research space_telescope ultraviolet_astronomy X-ray_astronomy CN "FVH: merged with orbiting_observatory (2007-NOV-15)" ## space_pollution space_pollution D "space pollution" BT pollution RT space_debris ## space_probe_instrument space_probe_instrument D "space probe instrument" NT space_telescope RT balloon-borne_instrument ground-based_astronomy rocket-borne_instrument satellite-borne_instrument space_probe ## space_probe space_probe ALT "probe" D "space probe" RT space_astronomy space_exploration space_observatory space_probe_instrument space_vehicle ## space_research space_research ALT "space science" D "space research" BT astronomical_research NT space_biology RT space_exploration space_law space_observatory ## space space D "space" RT general_theory_of_relativity special_theory_of_relativity vacuum ## space_telescope space_telescope D "space telescope" BT space_probe_instrument telescope NT X-ray_telescope gamma-ray_telescope ultraviolet_telescope RT artificial_satellite balloon-borne_instrument ground-based_astronomy rocket-borne_instrument satellite-borne_instrument space_exploration space_observatory N "named telescope not included" ## space-time_curvature space-time_curvature D "curvature of space-time" RT Dark_Energy cosmology general_theory_of_relativity ## space-time_singularity space-time_singularity D "space-time singularity" BT singularity RT Schwarzschild_metric black_hole naked_singularity quantum_cosmology ## space_vehicle space_vehicle D "space vehicle" NT space_debris RT artificial_satellite space_biology space_exploration space_probe N "named vehicles not included" ## special_theory_of_relativity special_theory_of_relativity D "special theory of relativity" BT general_theory_of_relativity RT space ## speckle_interferometry speckle_interferometry D "speckle interferometry" BT interferometry RT angular_diameter angular_resolution angular_separation seeing speckle ## speckle speckle D "speckle" RT atmospheric_refraction scintillation seeing speckle_interferometry ## spectral_band spectral_band D "spectral band" NT molecular_band RT molecular_line molecular_spectrum telluric_line ## spectral_classification spectral_classification D "spectral classification" BT classification NT Henry_Draper_system MK_classification RT Henry_Draper_catalog luminosity_classification spectral_type ## spectral_index spectral_index D "spectral index" RT radio_frequency radio_spectrum ## spectral_line spectral_line ALT "spectrum line" D "spectral line" NT D_line Fraunhofer_line absorption_line calcium_line carbon_line cyanogen_line emission_line hyperfine_line metal_line molecular_line technetium_line telluric_line ultraviolet_line RT equivalent_width fine_structure instrumental_profile line_blanketing line_blending line_broadening line_formation line_identification line_intensitite line_profile line_ratio natural_line_broadening natural_line_width spectral_type transition_probability N "not a complete list of terms" ## spectral_resolution spectral_resolution D "spectral resolution" BT resolution RT line_blending ## spectral_type spectral_type D "spectral type" RT A_star B_star F_star G_star K_star L_dwarf M_star N_star O_star R_star S_star T_dwarf line_width luminosity_class luminosity_classification spectral_classification spectral_line standard_star temperature N "not a complete list of terms" ## spectrum spectrum D "spectrum" NT abnormal_spectrum absorption_spectrum atomic_spectrum brillouin_spectrum continuous_spectrum echelle_spectrum emission_spectrum hydrogen_spectrum microwave_spectrum molecular_spectrum radio_spectrum three-dimensional_spectrum two-dimensional_spectrum vibrational_spectrum visible_spectrum RT Hertzsprung-Russell_diagram MK_classification absorption_line bremsstrahlung contiuum diffraction_grating emission_line energy_level equivalent_width fluorescence forbidden_line forbidden_transition free-free_emission hyperfine_line prism recombination_line resonance_line self-absorption spectroscopic_analysis spectroscopy stimulated_emission N "not a complete list of terms" ## spectrograph_slit spectrograph_slit ALT "slit" D "spectrograph slit" NT long_slit slit_mask RT long_slit_spectrum multi-slit_spectrograph spectrograph three-dimensional_spectrum two-dimensional_spectrum HN "FVH: new (2007-SEP-21)" ## spectrograph spectrograph D "spectrograph" BT instrument optical_instrument telescope_instrument NT Coude_spectrograph Fabry-Perot_spectrograph Fourier_spectrograph X-ray_spectrograph echelle_spectrograph gamma-ray_spectrograph grating_spectrograph grazing_incidence_spectrograph integral_field_spectrograph multi-channel_spectrograph multi-fiber_spectrograph multi-slit_spectrograph optical_spectrograph prism_spectrograph radio_spectrograph ultraviolet_spectrograph RT VPH_grating comparison_lamp diffraction_grating echelle_grating flat_field_lamp grism prism spectrograph_slit spectroheliograph spectroscopy CN "FVH: added RT SPECTROGRAPH_SLITS, NT INTEGRAL_FIELD_SPECTROGRAPHS, MULTI_FIBER_SPECTROGRAPHS, and MULTI_SLIT_SPECTROGRAPHS (2007-SEP-21)" ## spectrography spectrography ALT "spectrophotography" D "spectrography" BT spectroscopy photography N "see spectroscopy" ## spectroheliograph spectroheliograph D "spectroheliograph" RT coronagraph photoheliograph spectrograph ## spectrophotometer spectrophotometer D "spectrophotometer" BT photometer RT spectrophotometry telescope_instrument ## spectrophotometry spectrophotometry D "spectrophotometry" BT astronomical_technique observing_technique RT color optical_scanners photometry spectrophotometer spectroscopy standard_candle ## spectroscopic_analysis spectroscopic_analysis ALT "spectral analysis" D "spectroscopic analysis" RT Doppler_effect Milne_Eddington_approximation absorption_line collision_broadening continuous_spectrum emission_line maximum_entropy_method spectrum wave_motion waveform_analysis ## spectroscopic_binary_star spectroscopic_binary_star ALT "spectrum binary star" D "spectroscopic binary star" BT binary_star NT two-spectrum_binary_star RT Doppler_effect eclipsing_binary_star ellipsoidal_variable_star mass mass_function velocity_curve ## spectroscopy spectroscopy ALT "spectrometry" D "spectroscopy" BT astronomical_technique observing_technique NT Fourier_transform_spectroscopy Raman_spectroscopy X-ray_spectroscopy absorption_spectroscopy collision_spectroscopy gamma-ray_spectroscopy high-resolution_spectrosopy interference_spectrosocopy microwave_spectroscopy optical_spectroscopy spectrography three-dimensional_spectroscopy time-resolved_spectroscopy two-dimensional_spectroscopy RT collisional_excitation continuous_spectrum heterodyne pressure_broadening radial_velocity reseaux spectrum spectrograph spectrophotometry N "not a complete list of terms" ## spectrum_variable_star spectrum_variable_star D "spectrum variable star" BT Am_star Ap_star intrinsic_variable_star NT manganese_star RT alpha2_Canum_Venaticorum_star magnetic_star oblique_rotator ## spherical_aberration spherical_aberration D "spherical aberration" BT optical_aberration RT astigmatism chromatic_aberration comatic_aberration distortion field_curvature ## spherical_coordinate spherical_coordinate ALT "angular coordinate" D "spherical coordinate" RT coordinate_system position reference_system ## SPH_simulation SPH_simulation ALT "SPH" "smoothed-particle hydrodynamics" D "SPH simulation" BT numerical_simulation HN "FVH: new (2007-OCT-3)" ## spicule spicule D "spicule" NT macro_spicule RT Sun chromosphere ## spiral_arm spiral_arm ALT "arm" D "spiral arm" RT Galactic_structure galaxy_structure gas_distribution interstellar_magnetic_field interstellar_matter open_star_cluster pitch_angle population_I_star spiral_galaxy ## spiral_galaxy spiral_galaxy D "spiral galaxy" BT disk_galaxy galaxy NT Milky_Way_galaxy S_galaxy barred_spiral_galaxy RT late-type_galaxy pitch_angle spiral_arm ## s-process s-process ALT "s process" D "s-process" RT nucleosynthesis p_process r-process supernova ## S_star S_star ALT "Se star" D "S star" BT giant late-type_star RT barium_star carbon_star heavy_metal_star spectral_type technetium_star zirconium_star ## stability stability D "stability" RT vibration N "combine with other terms" ## standard_candle standard_candle D "standard candle" RT effective_temperature photometric_standard_star photometry spectrophotometry ## standard_epoch standard_epoch D "standard epoch" NT Besselian_epoch Julian_epoch ## standard_star standard_star D "standard star" NT comparison_star photometric_standard_star RT position spectral_type ## star_association star_association D "star association" NT O_association OB_association R_association T_association RT Goulds_belt open_star_cluster secular_parallax ## star_atlas star_atlas D "star atlas" BT atlas RT finding_chart map ## starburst_galaxy starburst_galaxy D "starburst galaxy" BT galaxy RT star_formation stellar_evolution ## star_cluster star_cluster ALT "cluster of star" D "star cluster" BT cluster NT globular_star_cluster open_star_cluster RT Poincare_theorem clustering initial_mass_function integrated_magnitude luminosity_function mass_function protocluster relaxation_time tidal_disruption tidal_radius velocity_dispersion velocity_distribution virial_theorem ## star_count star_count D "star count" RT Galactic_structure mass_function star_distribution statistics ## star_distribution star_distribution D "star distribution" RT star_count survey ## star_formation star_formation ALT "formation of star" D "star formation" RT Bok_globule Jeans_length birth_rate cometary_globule cooling_flow dark_nebula extrasolar_planet infrared_source pre-main_sequence_star protostar starburst_galaxy stellar_evolution stellar_ring ## Stark_broadening Stark_broadening D "Stark broadening" BT line_broadening RT Doppler_broadening Zeeman_splitting natural_line_width ## starspot starspot D "starspot" NT sunspot RT BY_Draconis_star RS_Canum_Venaticorum_star ## star star D "star" BT stellar_object NT Sun active_star barium_star binary_star bright_star central_star collapsed_star companion_star evolved_star faint_star field_star fundamental_star giant_branch_star halo_star helium-poor_star helium-rich_star high-luminosity_star high-mass_star high-velocity_star hydrogen_deficient_star hypergiant intermediate_population_star late-type_star lithium_star low-luminosity_star low-mass_star main_sequence_star massive_star metal-deficient_star metal-poor_star metal-rich_star population_I_star population_II_star population_III_star supernova young_star N "combine star or stellar with other terms" ## statistical_parallax statistical_parallax D "statistical parallax" BT parallax ## statistical_relation statistical_relation D "statistical relation" NT Faber-Jackson_relation Hubble_diagram Hubble_law Tully-Fisher_relation mass-luminosity_relation mass-radius_relation period-age_relation period-color_relation period-density_relation period-luminosity-color_relation period-luminosity_relation period-mass_relation period-radius_relation period-spectrum_relation radius-luminosity_relation ## statistics statistics D "statistics" RT Monte_Carlo_technique distribution_function radio_source_count selection_effect star_count N "combine with other terms" ## steady-state_theory steady-state_theory ALT "steady state theory" D "steady-state theory" BT cosmology RT Big_Bang_theory closed_universe open_universe ## stellar_atmosphere stellar_atmosphere D "stellar atmosphere" BT atmosphere NT solar_atmosphere RT chromosphere corona dredge_up limb_brightening limb_darkening line_broadening line_formation line_width negative_H_ion scale_height stellar_structure stellar_wind turbulence_star_atmosphere ## stellar_black_hole stellar_black_hole D "stellar black hole" BT black_hole collapsed_star stellar_object RT hypernova stellar_evolution ## stellar_dynamics stellar_dynamics D "stellar dynamics" RT Fokker-Planck_equation Galactic_rotation N-body_problem Poincare_theorem close_encounter encounter galaxy_rotation_curve proper_motion radial_velocity relaxation_time stellar_motion three-body_problem two-body_problem ## stellar_evolution stellar_evolution D "stellar evolution" BT evolution RT Henyey_track Hertzsprung-Russell_diagram Kerr_black_hole birth_rate carbon_burning chemical_evolution collapsed_star cosmology e-process evolutionary_track funneling giant gravitational_equilibrium helium_burning hydrogen_burning initial_mass_function inner_core instability_strip luminosity_function mass-loss protostar solar_interior star_formation starburst_galaxy stellar_black_hole stellar_interior CN "FVH: moved STAR_ORIGIN to RT (2007-OCT-1)" ## stellar_interior stellar_interior D "stellar interior" NT solar_interior RT Chandrasekhar_mass Chandrasekhar-Schoenberg_limit Eddington_limit Rosseland_opacity carbon_burning carbon_nitrogen_cycle core dredge_up gravity_wave helium_burning hydrogen_burning inner_core nuclear_fusion nucleosynthesis oxygen_burning proton-proton_reaction stellar_evolution stellar_structure temperature_zone ## stellar_motion stellar_motion D "stellar motion" BT motion RT Doppler_effect astrometry Local_Standard_of_Rest peculiar_motion peculiar_velocity proper_motion radial_velocity space_motion stellar_dynamics ## stellar_object stellar_object D "star-like object, including star, brown dwarf, and evolved stellar core (NS, BH, WD)" NT black_dwarf brown_dwarf neutron_star planetar star stellar_black_hole white_dwarf HN "FVH+ES: new (2007-OCT)" ## stellar_oscillation stellar_oscillation D "stellar oscillation" NT solar_oscillation RT asteroseismology seismology ## stellar_population stellar_population D "stellar population" RT disk_population halo_star intermediate_population_star population_I_star population_II_star population_III_star ## stellar_ring stellar_ring D "stellar ring" BT ring RT star_formation ## stellar stellar D "stellar" N "see sn for star" ## stellar_structure stellar_structure D "stellar structure" RT hydrostatic_equilibrium macroturbulence model polytrope solar_interior stellar_atmosphere stellar_interior ## stellar_wind stellar_wind D "stellar wind" BT mass-loss plasma NT solar_wind RT Poynting-Robertson_effect accretion_disk chromosphere circumstellar_shell interstellar_wind radiation_pressure shock stellar_atmosphere ## stimulated_emission stimulated_emission D "stimulated emission" RT laser maser population_inversion spectrum stimulated_radiation ## stimulated_radiation stimulated_radiation D "stimulated radiation" RT stimulated_emission ## stokes_parameter stokes_parameter D "Stokes parameter" RT light_polarization polarized_radiation ## stratopause stratopause D "stratopause" RT Earth_atmosphere mesosphere stratosphere ## stratosphere stratosphere D "stratosphere" RT Earth_atmosphere stratopause tropopause ## streak_photography streak_photography D "streak photography" BT photography ## streamer streamer D "streamer" RT comet tail ## stroboscope stroboscope D "stroboscope" BT instrument ## Stromgren_photometry Stromgren_photometry ALT "Stromgren uvby system" "four-color photometry" "uvby system" D "Stromgren photometry" BT medium_band_photometry photometric_system RT H_beta_photometry Kapteyn_selected_area e_region f_region ## Stromgren_sphere Stromgren_sphere D "Stromgren sphere" BT gaseous_sphere RT interstellar_matter ionization ionized_gas ## strong_gravitational_lensing strong_gravitational_lensing D "strong gravitational lensing (resolved)" BT gravitational_lensing HN "FVH: new (2007-OCT-8)" ## strong_interaction strong_interaction D "strong interaction" BT interaction RT nuclear_physics weak_interaction N "between atomic particle" ## strontium_star strontium_star D "strontium star" RT magnetic_star strontium ## strontium strontium ALT "Sr" D "strontium (atomic number 38)" BT fundamental_chemical_element RT strontium_star HN "FVH: new (2007-OCT-25)" ## structure structure D "structure" NT galaxy_structure RT planet N "combine with other terms" ## subdwarf subdwarf D "subdwarf star" BT subluminous_star NT A_subdwarf B_subdwarf F_subdwarf G_subdwarf K_subdwarf L_subdwarf M_subdwarf O_subdwarf T_subdwarf late-type_subdwarf RT Harman-Seaton_sequence dwarf ## subgiant subgiant D "subgiant star" BT post-main_sequence_star NT A_subgiant F_subgiant G_subgiant K_subgiant M_subgiant RT luminosity_classification ## subluminous_star subluminous_star D "subluminous star" NT degenerate_star subdwarf RT population_II_star ## submillimeter_astronomy submillimeter_astronomy D "submillimeter astronomy" BT radio_astronomy RT millimeter_astronomy radio_observatory submillimeter_radiation ## submillimeter_radiation submillimeter_radiation ALT "submillimeter wave" D "submillimeter radiation" BT electromagnetic_radiation RT submillimeter_astronomy CN "FVH: moved submillimeter_wave to here, cleaned up (2007-OCT-8)" ## subreflector subreflector D "subreflector" RT Cassegrain_antenna Cassegrain_focus radio_telescope secondary_mirror tertiary_mirror ## sulfur sulfur ALT "S" "sulphur" D "sulfur (atomic number 16)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## summer_solstice summer_solstice D "summer solstice" BT solstice RT Tropic_of_Cancer winter_solstice ## Sun Sun D "Sun" BT star NT active_Sun RT Fraunhofer_line Hanle_effect Solar_System active_prominence active_region bailys_bead bright_point chromosphere diamond_ring_effect flare granulation granule Local_Standard_of_Rest lunar_eclipse macro_spicule mottle photosphere prominence quiescent_prominence solar_constant solar_corona solar_eclipse solar_filament solar_physics solar-planetary_relation solar_surface solar-terrestrial_relation spicule N "combine Sun or solar with other terms; not a complete list of terms" ## sunlight sunlight D "sunlight" RT sky_brightness solar_constant twilight ## sunspot_cycle sunspot_cycle D "sunspot cycle" RT Maunder_minimum butterfly_diagram solar_activity solar_cycle sunspot ## sunspot_group sunspot_group D "sunspot group" NT bipolar_group RT solar_activity sunspot_number ## sunspot_number sunspot_number ALT "Wolf number" "relative sunspot number" D "sunspot number" RT Maunder_minimum butterfly_diagram solar_activity solar_cycle sunspot_group ## sunspot sunspot ALT "sun spot" D "sunspot" BT starspot RT Evershed-effect Wilson_effect active_Sun bipolar_group butterfly_diagram emerging_flux magnetic_field magnetic_storm penumbra plage prominence solar_activity solar_filament sunspot_cycle umbra CN "FVH: added ALT sun_spot, BT starspot (2007-OCT-8)" ## Sunyaev-Zeldovich_effect Sunyaev-Zeldovich_effect ALT "Sunyaev Zeldovich effect" D "Sunyaev-Zeldovich effect" RT X-ray_emission background_radiation galaxy_cluster intracluster_matter microwave_background ## supercluster supercluster D "supercluster" RT galaxy_cluster ## superconducting_tunnel_junction superconducting_tunnel_junction D "super-conducting tunnel junction detector" BT detector RT quantum_mechanics HN "FVH: new (2007-SEP-21)" ## supergalactic_coordinate_system supergalactic_coordinate_system D "supergalactic coordinate system" BT celestial_coordinate_system RT galaxy_cluster supergalactic_latitude supergalactic_longitude HN "ES: new (2007-OCT-8)" ## supergalactic_latitude supergalactic_latitude D "supergalactic latitude" BT latitude RT supergalactic_coordinate_system supergalactic_longitude HN "ES: (2007-OCT-8)" ## supergalactic_longitude supergalactic_longitude D "supergalactic longitude" BT longitude RT supergalactic_coordinate_system supergalactic_latitude HN "ES: (2007-OCT-8)" ## supergiant supergiant D "supergiant star" BT high-luminosity_star post-main_sequence_star NT A_supergiant B_supergiant F_supergiant G_supergiant K_supergiant O_supergiant early-type_supergiant late-type_supergiant RT Hubble_Sandage_variable_star Lc_variable_star R_Coronae_Borealis_star hypergiant irregular_variable_star semi-regular_variable_star supermassive_star ## supergranulation supergranulation D "supergranulation" BT granulation RT solar_surface ## superhump superhump D "superhump" BT variability RT SU_Ursae_Majoris_star accretion_disk precession ## supermassive_star supermassive_star D "supermassive star" RT massive_star supergiant ## supernova_envelope supernova_envelope D "supernova envelope" RT shock_wave supernova ## supernova supernova ALT "SN" D "supernova" BT high-luminosity_star star NT Type_Ia_supernova Type_Ib_supernova Type_Ic_supernova Type_II_supernova hypernova RT Opik_theory cataclysmic_variable_star e-process frozen_in_element gravitational_collapse mass-loss neutrino nova nuclear_fusion nucleosynthesis optical_outburst p_process pre-supernova progenitor pulsar r-process runaway_star s-process shock supernova_envelope support_system CN "FVH: moved presupernovas from UF to RT (2007-SEP-21)" ## supernova_remnant supernova_remnant ALT "SNR" D "supernova remnant" RT X-ray_source black_hole neutron_star pulsar radio_source white_dwarf white_hole ## support_system support_system D "support system" RT instrument supernova telescope N "combine with other terms" ## surface_brightness surface_brightness D "surface brightness" BT brightness RT L_galaxy gravity_darkening photosphere surface_photometry temperature von_Zeipel_theorem ## surface_gravity surface_gravity ALT "acceleration of gravity" D "surface gravity" RT diameter gravitational_force gravity_darkening line_width luminosity luminosity_classification mass ## surface_photometry surface_photometry ALT "area photometry" D "surface photometry" BT photometry RT drift_scan galaxy isophotal_diameter isophot nebula surface_brightness ## surface_property surface_property D "surface property" BT property RT albedo N "combine with other terms" ## surface_of_celestial_body surface_of_celestial_body ALT "surface celestial body" D "surface [celestial body]" NT canyon RT Moon dust_storm geology lunar_dome maria petrology photosphere planet satellite topography volatile volcano water_ice ## survey survey D "survey" NT X-ray_survey sky_survey ultraviolet_survey RT atlas catalog radio_source_count star_distribution ## SU_Ursae_Majoris_star SU_Ursae_Majoris_star D "SU Ursae Majoris star" BT dwarf_nova RT WZ_Sagittae_star superhump ## S_Vulpeculae_star S_Vulpeculae_star D "S Vulpeculae star" BT long_period_variable_star pulsating_variable_star semi-regular_variable_star RT Mira_variable_star RV_Tauri_star ## Swan_band Swan_band D "Swan band" BT molecular_band RT carbon_monoxide molecular_spectrum ## SX_Arietis_star SX_Arietis_star ALT "helium variable star" D "SX Arietis star" BT cataclysmic_variable_star dwarf_nova early-type_variable_star eruptive_binary_star magnetic_variable_star RT alpha2_Canum_Venaticorum_star CN "FVH: deleted wrong referernces to CV's (2007-OCT-2)" ## SX_Phoenicis_star SX_Phoenicis_star D "SX Phoenicis star" BT multi-periodic_variable_star population_II_star pulsating_variable_star ## symbiotic_nova symbiotic_nova D "symbiotic nova" BT nova symbiotic_star ## symbiotic_star symbiotic_star D "symbiotic star" BT emission_line_star eruptive_binary_star NT Z_Andromedae_star symbiotic_nova RT P_Cygni_line_profile X-ray_binary_star cataclysmic_variable_star dust_shell ## symbol symbol D "symbol" RT unit ## synchronous_detector synchronous_detector D "synchronous detector" BT detector ## synchronous_rotation synchronous_rotation D "synchronous rotation" BT rotation RT close_binary_star orbit rotating_star ## synchrotron_radiation synchrotron_radiation D "synchrotron radiation" BT electromagnetic_radiation radiation NT cyclotron_radiation gyrosynchrotron_radiation RT Razin_effect bremsstrahlung magnetohydrodynamics non-thermal_source radiation_mechanism relativistic_electron ## synodic_period synodic_period D "synodic period" RT Solar_System conjunction opposition planet syzygy ## system system D "system" NT absorption_line_system N "combine with other terms" ## syzygy syzygy D "syzygy" RT conjunction opposition planet synodic_period N "conjunction or opposition of planet" ## tail tail D "tail" RT comet head_tail_galaxy interacting_galaxy streamer ## tangential_velocity tangential_velocity D "tangential velocity" BT velocity RT orbital_velocity radial_velocity rotational_velocity ## tantalum tantalum ALT "Ta" D "tantalum (atomic number 73)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## t_array t_array D "t array" BT array radio_interferometer RT y_array ## T_association T_association ALT "T-association" D "T association" BT star_association RT FU_Orionis_star H_alpha_emission_line_star Herbig-Haro_object RW_Aurigae_star T_Tauri_star flare_star flash_star irregular_variable_star pre-main_sequence_star young_star_cluster young_star ## taxonomy taxonomy D "taxonomy" RT classification ## T_dwarf T_dwarf D "T dwarf" BT brown_dwarf RT T_subdwarf low-mass_star spectral_type HN "FVH: new (2007-OCT-2)" ## teaching_in_astronomy teaching_in_astronomy ALT "education" D "teaching in astronomy" ## technetium_line technetium_line D "technetium line" BT metal_line spectral_line RT technetium ## technetium_star technetium_star D "technetium star" RT N_star S_star technetium ## technetium technetium ALT "Tc" D "technetium (atomic number 43)" BT fundamental_chemical_element RT technetium_line technetium_star HN "FVH: new (2007-OCT-25)" ## tektite tektite D "tektite" BT meteorite NT australite bediasite indochinite moldavite ## telescope_array telescope_array D "telescope array" BT array RT filling_factor interferometer telescope ## telescope_construction telescope_construction D "telescope construction" RT telescope ## telescope_design telescope_design D "telescope design" RT telescope_mounting telescope ## telescope_instrument telescope_instrument ALT "telescope instrumentation" D "telescope instrument" BT instrument NT photometer polarimeter spectrograph RT control_system detector feed_horn feed remote_control_system spectrophotometer telescope N "not a complete list of terms" ## telescope_mirror telescope_mirror D "telescope mirror" BT mirror NT primary_mirror secondary_mirror tertiary_mirror RT telescope ## telescope_mounting telescope_mounting D "telescope mounting" NT altazimuth_mounting equatorial_mounting RT coelostat heliostat polar_axis siderostat telescope_design telescope ## telescope telescope D "telescope" BT optical_instrument NT Cassegrain_telescope Gregorian_telescope automated_telescope gamma-ray_telescope grazing_incidence_telescope infrared_telescope optical_telescope radio_telescope solar_telescope space_telescope RT antenna control_system dome drive focus guide_system observatory optical_aberration pointing_accuracy pointing_error remote_control_system support_system telescope_array telescope_construction telescope_design telescope_instrument telescope_mirror telescope_mounting vignetting N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list" ## television_camera television_camera ALT "TV camera" D "television camera" RT television television_detector two-dimensional_detector ## television_detector television_detector ALT "TV camera" "television camera tube" D "television detector" BT multi-channel_detector photoelectronic_device two-dimensional_detector RT CCD_detector television television_camera ## television television ALT "TV" D "television" RT television_camera television_detector ## telluric_line telluric_line D "telluric line" BT spectral_line RT Earth_atmosphere spectral_band N "from Earth's atmosphere" ## tellurium tellurium ALT "Te" D "tellurium (atomic number 52)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## temperature_control temperature_control D "temperature control" RT air_conditioning cryogenics cryostat dome temperature_distribution ventilation ## temperature_distribution temperature_distribution D "temperature distribution" RT temperature_control temperature_zone ## temperature_effect temperature_effect ALT "thermal effect" D "temperature effect" N "combine with other terms" ## temperature_fluctuation temperature_fluctuation D "temperature fluctuation" N "combine with other terms" ## temperature_scale temperature_scale D "temperature scale" NT absolute_temperature_scale celsius_temperature_scale RT Kelvin ## temperature temperature D "temperature" NT brightness_temperature effective_temperature electron_temperature ion_temperature RT absolute_temperature_scale celsius_temperature_scale color emissivity limb_brightening limb_darkening radiative_equilibrium spectral_type surface_brightness thermal_conductivity thermodynamics N "combine with other terms" ## temperature_zone temperature_zone D "temperature zone" RT atmosphere stellar_interior temperature_distribution ## terbium terbium ALT "Tb" D "terbium (atomic number 65)" BT fundamental_chemical_element rare_earth HN "FVH: new (2007-OCT-25)" ## terminator_line terminator_line D "terminator line" RT lunar_phase ## terrestrial_radiation terrestrial_radiation D "terrestrial radiation" BT atmospheric_radiation RT greenhouse_effect infrared_radiation N "ES: moved atmospheric_radiation from NT to BT (2007-OCT-8)" ## tertiary_mirror tertiary_mirror D "tertiary mirror" BT telescope_mirror RT Nasmyth_focus optical_telescope primary_mirror reflecting_telescope secondary_mirror subreflector HN "FVH: new (2007-SEP-21)" ## tertiary_star tertiary_star D "tertiary star" BT companion_star RT primary_star secondary_star HN "ES: new (2007-OCT-8)" ## testing testing D "testing" N "combine with other terms" ## thallium thallium ALT "Tl" D "thallium (atomic number 81)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## theoretical_astrophysics theoretical_astrophysics D "theoretical astrophysics" BT astrophysics CN "FVH: moved ASTROPHYSICS to BT (2007-OCT-1)" ## theory theory D "theory" RT research N "combine with other terms" ## thermal_conductivity thermal_conductivity D "thermal conductivity" RT conduction temperature ## thermal_emission thermal_emission D "thermal emission" BT emission_spectrum RT free-free_emission infrared_emission ## thermal_equilibrium thermal_equilibrium D "thermal equilibrium" RT Saha_equation local_thermodynamic_equilibrium thermal_instability thermodynamic_equilibrium thermodynamics ## thermal_history thermal_history D "thermal history" N "combine with other terms" ## thermal_instability thermal_instability D "thermal instability" RT convection local_thermodynamic_equilibrium thermal_equilibrium thermodynamic_equilibrium turbulence_Earth_atmosphere turbulence_star_atmosphere ## thermal_property thermal_property D "thermal property" BT property N "combine with other terms" ## thermal_radiation thermal_radiation D "thermal radiation" BT electromagnetic_radiation radiation RT Johnson_noise black_body_radiation infrared_radiation ## thermal_stability thermal_stability D "thermal stability" RT Rayleigh_number local_thermodynamic_equilibrium thermodynamic_equilibrium ## thermal_structure thermal_structure D "thermal structure" RT convection turbulence_Earth_atmosphere turbulence_star_atmosphere N "combine with other terms" ## thermionic_emission thermionic_emission ALT "dark current" D "thermionic emission" RT cathode electron ion ## thermodynamic_equilibrium thermodynamic_equilibrium D "thermodynamic equilibrium" NT local_thermodynamic_equilibrium RT energy-transfer thermal_equilibrium thermal_instability thermal_stability thermodynamics ## thermodynamics thermodynamics D "thermodynamics" RT adiabatic_process energy-transfer enthalpy entropy local_thermodynamic_equilibrium plasma temperature thermal_equilibrium thermodynamic_equilibrium ## thermoluminescence thermoluminescence D "thermoluminescence" BT luminescence ## thermonuclear_reaction thermonuclear_reaction D "thermonuclear reaction" N "see nuclear fusion" ## thermosphere thermosphere D "thermosphere" RT Earth_atmosphere exosphere ionosphere mesopause upper_atmosphere ## thickness thickness D "thickness" N "combine with other terms" ## thin_film thin_film D "thin film" BT optical_film NT aluminum_coating antireflection_coating silver_coating RT coating mirror optical_surface reflection vacuum_technique vapor_deposition ## Thomson_scattering Thomson_scattering D "Thomson scattering" BT Compton_scattering light_scattering radiation_scattering RT Rayleigh_scattering ## thorium thorium ALT "Th" D "thorium (atomic number 90)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## three-body_problem three-body_problem ALT "three body problem" D "three-body problem" RT N-body_problem celestial_mechanics orbit perturbation stellar_dynamics two-body_problem ## three-dimensional_spectrum three-dimensional_spectrum ALT "three dimensional spectrum" D "three-dimensional spectrum" BT spectrum RT extended_object integral_field_spectrograph long_slit_spectrum multi-fiber_spectrograph multi-slit_spectrograph spectrograph_slit three-dimensional_spectroscopy two-dimensional_spectroscopy HN "FVH: new (2007-SEP-21)" ## three-dimensional_spectroscopy three-dimensional_spectroscopy ALT "three dimensional spectroscopy" D "three-dimensional spectroscopy" BT spectroscopy RT three-dimensional_spectrum ## thulium thulium ALT "Tm" D "thulium (atomic number 69)" BT fundamental_chemical_element rare_earth HN "FVH: new (2007-OCT-25)" ## tidal_disruption tidal_disruption D "tidal disruption" RT Roche_limit differential_rotation star_cluster tidal_distortion tidal_friction tidal_interaction tidal_radius ## tidal_distortion tidal_distortion D "tidal distortion" RT differential_rotation interacting_galaxy tidal_disruption tidal_friction tidal_interaction ## tidal_friction tidal_friction D "tidal friction" RT Earth-Moon_system close_binary_star interacting_binary_star interacting_galaxy tidal_disruption tidal_distortion tidal_interaction tide ## tidal_interaction tidal_interaction D "tidal interaction" RT Roche_lobe interacting_binary_star interacting_galaxy tidal_disruption tidal_distortion tidal_friction ## tidal_radius tidal_radius D "tidal radius" RT star_cluster tidal_disruption ## tide tide D "tide" NT atmospheric_tide ocean_tide polar_tide RT tidal_friction ## time_measurement time_measurement ALT "time determination" D "time measurement" RT time ## time-resolved_spectroscopy time-resolved_spectroscopy D "time-resolved spectroscopy" BT spectroscopy RT high-speed_photometer variable_star ## time_signal time_signal D "time signal" RT global_positioning_system time_standard time_synchronization ## time_standard time_standard D "time standard" RT atomic_clock clock global_positioning_system time_signal time_synchronization ## time_synchronization time_synchronization ALT "time synchronisation UK" D "time synchronization" RT atomic_clock global_positioning_system radio_interferometry time_signal time_standard very_long_baseline_interferometry ## time time D "time" NT Universal_Time civil_time dynamical_time ephemeris_time mean_solar_time sidereal_time RT Besselian_epoch Earth_orbit Earth_rotation Gregorian_calendar Julian_Date Julian_epoch astrometric_instrument atomic_clock calendar chronometer clock ephemeris epoch general_theory_of_relativity time_measurement transit_instrument transit_time year ## timing_equipment timing_equipment ALT "timing device" D "timing equipment" NT clock pendulum ## tin tin ALT "Sn" D "tin (atomic number 50)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## tip-tilt_mirror tip-tilt_mirror ALT "tip tilt mirror" D "tip-tilt mirror" RT active_optics seeing segmented_optics ## titanium_oxide titanium_oxide ALT "TiO" D "TiO molecule" RT L_dwarf M_star oxygen titanium HN "FVH: new (2007-OCT-2)" ## titanium titanium ALT "Ti" D "titanium (atomic number 22)" BT fundamental_chemical_element RT titanium_oxide HN "FVH: new (2007-OCT-25)" ## topography topography D "topography" RT Earth planet satellite surface_of_celestial_body N "combine with other terms" ## torus torus D "torus" RT circumstellar_disk interstellar_matter ## total_eclipse total_eclipse D "total eclipse" BT eclipse RT annular_eclipse eclipsing_binary_star partial_eclipse umbra ## trace_element trace_element D "trace element" BT chemical_element RT metal_abundance ## tracking tracking D "tracking" RT autoguider control_system pointing_accuracy pointing_error ## trajectory trajectory D "trajectory" RT orbit ## transfer_function transfer_function D "transfer function" NT modulation_transfer_function optical_transfer_function point_spread_function ## transit_circle transit_circle D "transit circle" BT transit_instrument RT transit_telescope ## transit_instrument transit_instrument D "transit instrument" BT astrometric_instrument NT meridian_circle transit_circle transit_telescope RT astrometry meridian_observation time transit ## transition_probability transition_probability D "transition probability" RT g_value gf_value line_formation line_width oscillator_strength spectral_line ## transition_region transition_region D "transition region" RT chromosphere solar_corona ## transit transit D "transit" RT astrometry eclipse occultation transit_instrument ## transit_telescope transit_telescope D "transit telescope" BT transit_instrument NT zenith_telescope RT meridian_observation transit_circle transit_time ## transit_time transit_time D "transit time" RT Right_Ascension hour_angle meridian_observation sidereal_time time transit_telescope ## transmission_grating transmission_grating D "transmission grating" BT diffraction_grating NT objective_grating RT VPH_grating echelle_grating grism reflection_grating ## transmission transmission D "transmission" RT absorption optics reflection refraction transparency N "combine with other terms" ## trans-Neptunian_object trans-Neptunian_object ALT "TNO" D "trans-Neptunian object" NT Edgeworth-Kuiper_belt_object RT Edgeworth-Kuiper_belt Oort_cloud Solar_System asteroid HN "FVH: new (2007-OCT-2)" ## transparency transparency D "transparency" RT absorption_coefficient atmospheric_window opacity transmission ## transplutonian_planet transplutonian_planet D "transplutonian planet" RT Solar_System ## transport_process transport_process D "transport process" RT radiative_transfer ## transverse_velocity transverse_velocity D "transverse velocity" BT velocity RT proper_motion radial_velocity space_motion ## trigonometric_parallax trigonometric_parallax D "trigonometric parallax" BT parallax RT Astronomical_Unit distance nearby_star ## triple_star triple_star D "triple star" BT multiple_star CN "FVH: moved MULTIPLE_STARS to BT (2007-OCT-1)" ## tritium tritium D "tritium, an isotope of hydrogen" BT hydrogen RT isotope ## Trojan_group Trojan_group D "Trojan group" BT minor_planet_family RT Amor_group Apollo_group ## tropical_year tropical_year D "tropical year" BT year RT Earth_orbit ## Tropic_of_Cancer Tropic_of_Cancer D "Tropic of Cancer" RT Tropic_of_Capricorn solstice summer_solstice ## Tropic_of_Capricorn Tropic_of_Capricorn D "Tropic of Capricorn" RT Tropic_of_Cancer solstice winter_solstice ## tropopause tropopause D "tropopause" RT Earth_atmosphere stratosphere troposphere ## troposphere troposphere D "troposphere" RT Earth Earth_atmosphere exosphere tropopause ## true_anomaly true_anomaly D "true anomaly" BT orbital_anomaly CN "FVH: moved ANOMALY to BT (2007-OCT-1)" ## true_position true_position D "true position" BT position RT apparent_position astrometry coordinate_system ## T_subdwarf T_subdwarf D "T subdwarf" BT brown_dwarf subdwarf RT T_dwarf HN "FVH: new (2007-OCT-9)" ## T_Tauri_star T_Tauri_star ALT "TTS" "YY Orionis star" D "T Tauri star" BT emission_line_star irregular_variable_star pre-main_sequence_star NT FU_Orionis_star classical_T_Tauri_star weak-line_T_Tauri_star RT Herbig-Haro_object RW_Aurigae_star T_association emission_nebula protostar CN "FVH: moved yy_orinois_star to ALT, added NT CLASSICAL_T_TAURI_STARS and WEAK_LINE_T_TAURI_STARS (2007-SEP-24)" ## Tully-Fisher_relation Tully-Fisher_relation D "Tully-Fisher relation" BT statistical_relation RT cosmology galaxy line_width redshift ## tungsten tungsten ALT "W" D "tungsten (atomic number 74)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## turbidity turbidity D "turbidity" RT halation photographic_emulsion ## turbulence_Earth_atmosphere turbulence_Earth_atmosphere D "turbulence [Earth atmosphere]" NT macroturbulence microturbulence RT Earth_atmosphere convection point_spread_function scintillation seeing thermal_instability thermal_structure N "in Earth's atmosphere" ## turbulence_star_atmosphere turbulence_star_atmosphere D "turbulence [star atmosphere]" NT macroturbulence microturbulence RT convection line_broadening stellar_atmosphere thermal_instability thermal_structure N "in stellar atmosphere or in interstellar matter" ## turnoff_point turnoff_point D "turnoff point" RT Hertzsprung-Russell_diagram age giant_branch globular_star_cluster main_sequence open_star_cluster ## twilight twilight D "twilight" RT Earth_atmosphere sky_brightness sunlight ## two-body_problem two-body_problem ALT "two body problem" D "two-body problem" RT Earth-Moon_system N-body_problem binary_star celestial_mechanics planet stellar_dynamics three-body_problem ## two-color_diagram two-color_diagram ALT "two color diagram" D "two-color diagram" RT color_index photometry ## two-color_photometry two-color_photometry ALT "two color photometry" D "two-color photometry" BT broad_band_photometry NT BV_photometry RT Johnson_photometry Sloan_photometry ## two-dimensional_detector two-dimensional_detector ALT "two dimensional detector" D "two-dimensional detector" BT detector NT CCD_detector image_tube television_detector RT charge-coupled_device charge-injection_device charge-transfer_device flat_field image_processing pixel television_camera ## two-dimensional_spectrum two-dimensional_spectrum ALT "two dimensional spectrum" D "two-dimensional spectrum" BT spectrum RT extended_object long_slit_spectrum spectrograph_slit two-dimensional_spectroscopy N "FVH: added RT SPECTROGRAPH_SLITS (2007-SEP-21)" ## two-dimensional_spectroscopy two-dimensional_spectroscopy ALT "two dimensional spectroscopy" D "two-dimensional spectroscopy" BT spectroscopy RT three-dimensional_spectrum two-dimensional_spectrum ## two-spectrum_binary_star two-spectrum_binary_star ALT "spectrum binary star" "two spectrum binary star" D "two-spectrum binary star" BT spectroscopic_binary_star ## Type_Ia_supernova Type_Ia_supernova D "Type Ia supernova" BT supernova RT Type_Ib_supernova Type_Ic_supernova Type_II_supernova cosmology HN "FVH: new (2007-OCT-1)" ## Type_Ib_supernova Type_Ib_supernova D "Type Ib supernova" BT supernova RT Type_Ia_supernova Type_Ic_supernova Type_II_supernova HN "FVH: new (2007-OCT-1)" ## Type_Ic_supernova Type_Ic_supernova D "Type Ic supernova" BT supernova RT Type_Ia_supernova Type_Ib_supernova Type_II_supernova HN "FVH: new (2007-OCT-1)" ## Type_II_supernova Type_II_supernova D "Type II supernova" BT supernova RT Type_Ia_supernova Type_Ib_supernova Type_Ic_supernova HN "FVH: new (2007-OCT-1)" ## U_Geminorum_star U_Geminorum_star ALT "SS Cygni star" D "U Geminorum star" BT dwarf_nova RT UV_Persei_star emission_line_star CN "FVH: update (2007-SEP-24)" ## ultraviolet_astronomy ultraviolet_astronomy ALT "UV astronomy" D "ultraviolet astronomy" BT space_astronomy RT balloon-borne_instrument rocket-borne_instrument satellite-borne_instrument space_observatory ultraviolet_telescope ## ultraviolet_background ultraviolet_background D "ultraviolet background" BT background_radiation ultraviolet_radiation RT X-ray_background gamma-ray_background microwave_background radio_background ## ultraviolet_camera ultraviolet_camera D "ultraviolet camera" BT camera ## ultraviolet_color ultraviolet_color D "ultraviolet color" RT ultraviolet_photometry ## ultraviolet_continuum ultraviolet_continuum D "ultraviolet continuum" BT continuum_radiation ultraviolet_radiation ## ultraviolet_detector ultraviolet_detector D "ultraviolet detector" BT detector RT photometer ## ultraviolet_excess_star ultraviolet_excess_star ALT "UV excess star" D "ultraviolet excess star" NT RW_Aurigae_star RT metal-deficient_star metal-poor_star ## ultraviolet_extinction ultraviolet_extinction D "ultraviolet extinction" RT atmospheric_extinction N "in Earth's atmosphere" ## ultraviolet_filter ultraviolet_filter D "ultraviolet filter" RT interference_filter optical_filter ## ultraviolet_line ultraviolet_line D "ultraviolet line" BT spectral_line RT line_spectrum ## ultraviolet_luminosity ultraviolet_luminosity D "ultraviolet luminosity" BT luminosity ## ultraviolet_observatory ultraviolet_observatory D "ultraviolet observatory" BT observatory NT Hubble_Space_Telescope RT ultraviolet_radiation HN "FVH: new (2007-NOV-1)" ## ultraviolet_photography ultraviolet_photography D "ultraviolet photography" BT photography RT camera ## ultraviolet_photometry ultraviolet_photometry D "ultraviolet photometry" BT broad_band_photometry medium_band_photometry photometry RT U_magnitude ultraviolet_color ultraviolet_radiation ## ultraviolet_radiation ultraviolet_radiation ALT "ultraviolet_light" D "ultraviolet radiation" BT electromagnetic_radiation radiation NT extreme_ultraviolet_radiation far_ultraviolet_radiation near_ultraviolet_radiation ultraviolet_background ultraviolet_continuum RT Cerenkov_radiation Lyman_continuum Lyman_series black_body_radiation line_blanketing ultraviolet_observatory ultraviolet_photometry ultraviolet_spectrograph CN "FVH: change BT electromagnetic_wave to BT electromagnetic_radiation (2007-OCT-8)" ## ultraviolet_source ultraviolet_source ALT "ultraviolet object" D "ultraviolet source" NT early-type_star ## ultraviolet_spectrograph ultraviolet_spectrograph D "ultraviolet spectrograph" BT spectrograph RT ultraviolet_radiation ## ultraviolet_survey ultraviolet_survey D "ultraviolet survey" BT survey RT catalog ## ultraviolet_telescope ultraviolet_telescope D "ultraviolet telescope" BT space_telescope RT ultraviolet_astronomy ## ultraviolet ultraviolet ALT "UV" D "ultraviolet" N "combine with other terms" ## U_magnitude U_magnitude D "U magnitude" BT apparent_magnitude RT Bessel_photometry Johnson_photometry ultraviolet_photometry ## umbra umbra D "umbra" RT Wilson_effect eclipse lunar_eclipse penumbra solar_eclipse sunspot total_eclipse zone_of_totality ## underabundance underabundance D "underabundance" BT abundance RT overabundance HN "ES: new (2007-OCT-8)" ## unit unit D "unit" RT metrology symbol N "of measurement" ## Universal_Time Universal_Time ALT "U.T." "UT" D "universal time" BT time NT UT1 coordinated_Universal_Time RT civil_time ephemeris_time mean_solar_time solar_day year ## universe universe ALT "cosmos" D "universe" RT Dark_Energy cosmogony cosmology large_scale_structure metagalaxy N "see also under cosmology" ## unsharp_masking unsharp_masking D "unsharp masking" RT photographic_processing photography ## upper_atmosphere upper_atmosphere D "upper atmosphere" RT Earth_atmosphere aurora exosphere ionosphere magnetosphere mesosphere thermosphere van_Allen_radiation_belt N "Earth's atmosphere" ## upsilon_Sagittarii_star upsilon_Sagittarii_star D "upsilon Sagittarii star" BT eclipsing_binary_star ## uranium uranium ALT "U" D "uranium (atomic number 92)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## Uranus Uranus D "Uranus" BT Jovian_planet planet RT Solar_System HN "FVH: new (2007-SEP-24)" ## urca_process urca_process D "urca process" BT nuclear_reaction ## UT1 UT1 D "UT1" BT Universal_Time RT coordinated_Universal_Time HN "FVH: new (2007-OCT-3)" ## UU_Herculis_star UU_Herculis_star D "UU Herculis star" BT F_supergiant irregular_variable_star post-asymptotic_giant_branch CN "FVH: corrected content (2007-OCT-5)" ## UV_Ceti_star UV_Ceti_star D "UV Ceti star" BT flare_star variable_source RT flash_star ## UV_Persei_star UV_Persei_star D "UV Persei star" BT cataclysmic_variable_star RT U_Geminorum_star dwarf_nova ## UX_Ursae_Majoris_star UX_Ursae_Majoris_star D "UX Ursae Majoris-like star" BT nova-like_variable RT AM_Canum_Venaticorum_star Z_Camelopardalis_star dwarf_nova ## vacuum_technique vacuum_technique D "vacuum technique" RT aluminizing aluminum_coating outgassing thin_film vapor_deposition ## vacuum vacuum D "vacuum" RT pressure space ## vanadium vanadium ALT "V" D "vanadium (atomic number 23)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## van_Allen_radiation_belt van_Allen_radiation_belt D "van Allen belt" "van Allen radiation belt" BT radiation_belt RT magnetohydrodynamics upper_atmosphere ## vapor_deposition vapor_deposition D "vapor deposition" RT aluminum_coating coating thin_film vacuum_technique ## variability variability D "variability" NT superhump RT high-state low-state N "combine with other terms" ## variable_source variable_source D "variable source" BT radio_source source NT BL_Lacertae_object UV_Ceti_star active_galactic_nucleus RT high-state low-state quasar ## variable_star variable_star D "variable star" NT cataclysmic_variable_star eclipsing_binary_star ellipsoidal_variable_star intrinsic_variable_star irregular_variable_star peculiar_variable_star pulsating_variable_star semi-regular_variable_star RT H_alpha_emission_line_star He_II_ionization_zone OH_IR_star Purkinje_effect amplitude comparison_star fundamental_frequency high-speed_photometer light_curve maximum minimum period period_determination phase_shift phase_wave time-resolved_spectroscopy velocity_curve visual_observation N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list ## velocity_curve velocity_curve D "velocity curve" RT light_curve maximum minimum period phase_shift phase_wave spectroscopic_binary_star variable_star velocity ## velocity_dispersion velocity_dispersion D "velocity dispersion" RT galaxy_cluster luminosity-dispersion_relation missing_mass star_cluster virial_theorem ## velocity_distribution velocity_distribution D "velocity distribution" RT galaxy_cluster star_cluster velocity virial_theorem ## velocity_ellipsoid velocity_ellipsoid D "velocity ellipsoid" RT velocity ## velocity_field velocity_field D "velocity field" RT galaxy shock_wave velocity N "combine with other terms" ## velocity_of_light velocity_of_light ALT "speed of light" D "velocity of light" BT physical_constant velocity RT apparent_superluminal_motion ergosphere event_horizon light_cone light_year ## velocity_space velocity_space D "velocity space" RT phase_space velocity ## velocity velocity D "velocity" NT angular_velocity escape_velocity heliocentric_velocity orbital_velocity parabolic_velocity peculiar_velocity radial_velocity relativistic_velocity rotational_velocity tangential_velocity transverse_velocity velocity_of_light RT high-velocity_cloud high-velocity_star kinematics momentum velocity_curve velocity_distribution velocity_ellipsoid velocity_field velocity_space N "ES: added rotational_velocity (2007-OCT-11)" "combine with other terms" ## ventilation ventilation D "ventilation" RT air_conditioning dome_seeing dome temperature_control N "combine with other terms" ## Venus Venus D "Venus" BT planet RT Solar_System ashen_light ## vernal_equinox vernal_equinox D "vernal equinox" BT equinox RT autumnal_equinox ## vertical_circle vertical_circle D "vertical circle" RT altazimuth_mounting meridian_circle ## Very_Large_Array Very_Large_Array ALT "VLA" D "Very Large Array" BT very_long_baseline_interferometer ## very_large_telescope very_large_telescope D "very large telescope" BT optical_telescope RT multiple_mirror_telescope segmented_optics ## very_long_baseline_interferometer very_long_baseline_interferometer ALT "VLBI" D "very long baseline interferometer" BT array interferometer radio_interferometer radio_telescope NT Very_Large_Array RT long_baseline_interferometer ## very_long_baseline_interferometry very_long_baseline_interferometry ALT "VLBI" D "very long baseline interferometry" BT interferometry radio_interferometry RT atomic_clock long_baseline_interferometry radio_astrometry time_synchronization ## vibrational_spectrum vibrational_spectrum D "vibrational spectrum" BT spectrum RT molecular_spectrum q_branch ## vibration vibration D "vibration" RT amplitude antinode node seismology stability ## vignetting vignetting D "vignetting" RT field_of_view telescope wide-field_telescope ## Vilnius_photometry Vilnius_photometry D "Vilnius photometry" BT medium_band_photometry RT Geneva_photometry ## virial_theorem virial_theorem D "virial theorem" RT galaxy_cluster gravitation radial_velocity star_cluster velocity_dispersion velocity_distribution ## virtual_observatory virtual_observatory D "virtual observatory" RT data_center data_retrieval database HN "FVH: new (2007-SEP-24)" ## viscosity viscosity D "viscosity" RT plasma ## visibility_function visibility_function D "visibility function" RT aperture_synthesis interference_fringe interferometry ## visible_radiation visible_radiation ALT "light" D "visible radiation" BT electromagnetic_radiation NT polarized_light RT color darkness gravitational_lensing light_absorption light_interference light_scattering luminescence refraction visible_spectrum CN "FVH: combined with light (2007-OCT-8)" ## visible_spectrum visible_spectrum D "visible spectrum" BT spectrum RT continuous_spectrum visible_radiation ## vision vision D "vision" NT color_vision RT dark_adaption image visual_acuity ## visual_acuity visual_acuity D "visual acuity" RT resolution vision ## visual_binary_star visual_binary_star D "visual binary star" BT binary_star wide_binary_star RT occulting_disk orbital_motion separation visual_observation N "see also optical double star" ## visual_magnitude visual_magnitude D "visual magnitude" RT Purkinje_effect V_magnitude photovisual_magnitude ## visual_observation visual_observation D "visual observation" RT Purkinje_effect variable_star visual_binary_star ## V_magnitude V_magnitude D "V magnitude" BT apparent_magnitude RT Bessel_photometry Johnson_photometry photovisual_magnitude visual_magnitude ## Voigt_profile Voigt_profile D "Voigt profile" RT absorption_line line_spectrum ## volatile volatile D "volatile" RT planet surface_of_celestial_body ## volcano volcano D "volcano" RT crater planet satellite surface_of_celestial_body ## von_Zeipel_theorem von_Zeipel_theorem D "von Zeipel theorem" RT binary_star gravity gravity_darkening rotating_star surface_brightness ## VPH_grating VPH_grating D "VPH grating" BT diffraction_grating RT spectrograph transmission_grating HN "FVH: new (2007-SEP-21)" ## VY_Sculpturis_star VY_Sculpturis_star D "VY Sculpturis star" BT nova-like_variable RT Z_Camelopardalis_star ## Walraven_photometry Walraven_photometry ALT "VBLUW photometry" D "Walraven photometry" BT medium_band_photometry photometric_system ## water_ice water_ice ALT "ice" D "water ice" RT planet surface_of_celestial_body water ## water_maser water_maser D "water maser" BT maser RT OH_maser SiO_maser water ## water_vapor water_vapor D "water vapor" RT atmosphere planet water ## water water D "water" BT interstellar_molecule RT water_ice water_maser water_vapor ## waveform_analysis waveform_analysis D "waveform analysis" RT Fourier_analysis period_determination spectroscopic_analysis ## waveguide waveguide D "waveguide" NT optical_waveguide radio_waveguide ## wavelength wavelength D "wavelength" RT acoustic_wave electromagnetic_radiation frequency N "combine with other terms" ## wave_motion wave_motion D "wave motion" BT motion RT interference_wave spectroscopic_analysis wave_propagation ## wave_propagation wave_propagation D "wave propagation" RT refraction shock_wave wave_motion wave ## wave wave D "wave" NT acoustic_wave drift_wave electromagnetic_radiation gravitational_wave gravity_wave RT oscillation wave_propagation ## WCN_star WCN_star D "WCN star" BT Wolf-Rayet_star CN "FVH: moved WOLF_RAYET_STARS to BT (2007-OCT-1)" ## WC_star WC_star D "WC star" BT Wolf-Rayet_star CN "FVH: moved WOLF_RAYET_STARS to BT (2007-OCT-1)" ## weak_G_band_star weak_G_band_star D "weak G band star" BT giant metal-poor_star ## weak_gravitational_lensing weak_gravitational_lensing D "weak gravitational lensing (resolved)" BT gravitational_lensing HN "FVH: new (2007-OCT-8)" ## weak_interaction weak_interaction D "weak interaction" BT interaction NT Fermi_interaction RT nuclear_physics strong_interaction N "between atomic particles" ## weak-line_T_Tauri_star weak-line_T_Tauri_star ALT "WTTS" D "weak-line T Tauri star" BT T_Tauri_star HN "FVH: new (2007-SEP-24)" ## weather_station weather_station D "weather station" BT measuring_instrument RT altimeter anemometer barometer wind_vane HN "FVH: new (2007-SEP-21)" ## webcam webcam D "webcam" BT camera HN "FVH: new (2007-SEP-21)" ## white_dwarf white_dwarf D "white dwarf star" BT compact_object degenerate_dwarf evolved_star stellar_object NT DA_star DB_star DO_star ZZ_Ceti_star RT Chandrasekhar_mass X-ray_pulsar black_dwarf cataclysmic_variable_star collapsed_star supernova_remnant CN "FVH: moved DA_star to NT, added DB_STARS (2007-OCT-1)" ## white_hole white_hole D "white hole" RT black_hole cosmology gravitational_lensing naked_singularity supernova_remnant ## wide-angle_lens wide-angle_lens ALT "wide angle lens" D "wide-angle lens" RT all-sky_camera all-sky_photography camera ## wide_binary_star wide_binary_star D "wide binary star" BT binary_star NT visual_binary_star CN "FVH: moved BINARY_STARS to BT and VISUAL_BINARY_STARS to NT (2007-OCT-1)" ## wide-field_telescope wide-field_telescope ALT "wide field telescope" D "wide-field telescope" BT reflecting_telescope NT Baker-Nunn_camera all-sky_camera RT Bouwers_telescope Maksutov_telescope Schmidt_telescope vignetting ## Wilson-Bappu_effect Wilson-Bappu_effect ALT "Wilson Bappu effect" D "Wilson-Bappu effect" RT Ca_II_emission_line K_line absolute_magnitude late-type_star ## Wilson_effect Wilson_effect D "Wilson effect" RT penumbra sunspot umbra ## window window D "window" NT Galactic_window atmospheric_window RT interstellar_absorption N "combine with other terms" ## wind_vane wind_vane D "wind vane" BT measuring_instrument RT anemometer weather_station HN "FVH: new (2007-SEP-21)" ## winter_solstice winter_solstice D "winter solstice" BT solstice RT Tropic_of_Capricorn summer_solstice ## WN_star WN_star D "WN star" BT Wolf-Rayet_star CN "FVH: moved WOLF_RAYET_STARS to BT (2007-OCT-1)" ## Wolf_diagram Wolf_diagram D "Wolf diagram" RT dark_nebula interstellar_absorption ## Wolf-Rayet_star Wolf-Rayet_star D "Wolf-Rayet star" BT early-type_emission_star NT WC_star WCN_star WN_star WR_star RT O_star carbon_star circumstellar_envelope ejecta mass-loss ## WR_star WR_star D "WR star" BT Wolf-Rayet_star CN "FVH: moved WOLF_RAYET_STARS to BT (2007-OCT-1)" ## W_Ursae_Majoris_star W_Ursae_Majoris_star D "W Ursae Majoris star" BT detached_binary_star eclipsing_binary_star RT Algol_variable_star ## W_Virginis_star W_Virginis_star D "W Virginis star" BT population_II_Cepheid pulsating_variable_star NT BL_Herculis_star RT Cepheid RR_Lyrae_star ## WZ_Sagittae_star WZ_Sagittae_star D "WZ Sagittae star" BT dwarf_nova long_period_variable_star RT SU_Ursae_Majoris_star ## xenon xenon ALT "Xe" D "xenon (atomic number 54)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## X-ray_absorption X-ray_absorption D "X-ray absorption" BT X-ray_spectrum RT X-ray_emission ## X-ray_astronomy X-ray_astronomy D "X-ray astronomy" BT space_astronomy RT X-ray_spectrograph X-ray_telescope balloon-borne_instrument rocket-borne_instrument satellite-borne_instrument space_observatory ## X-ray_background X-ray_background D "X-ray background" BT background_radiation RT X-ray_radiation gamma-ray_background microwave_background radio_background ultraviolet_background ## X-ray_binary_star X-ray_binary_star D "X-ray binary star" BT X-ray_source eruptive_binary_star interacting_binary_star NT cataclysmic_variable_star high-mass_X-ray_binary_star low-mass_X-ray_binary_star RT HZ_Herculis_star X-ray_burst X-ray_nova X-ray_pulsar X-ray_star black_hole dwarf_nova neutron_star symbiotic_star ## X-ray_bright_point X-ray_bright_point D "X-ray bright point" RT close_binary_star interacting_binary_star ## X-ray_burst X-ray_burst D "X-ray burst" BT burst RT HZ_Herculis_star X-ray_binary_star X-ray_transient burster gamma-ray_burst neutron_star optical_burst radio_burst rapid_burst ## X-ray_continuum X-ray_continuum D "X-ray continuum" BT X-ray_spectrum continuum_radiation ## X-ray_detector X-ray_detector D "X-ray detector" BT detector RT proportional_counter ## X-ray_diffraction X-ray_diffraction D "X-ray diffraction" BT diffraction RT X-ray_scattering X-ray_spectroscopy ## X-ray_emission X-ray_emission D "X-ray emission" BT X-ray_spectrum emission_spectrum RT Sunyaev-Zeldovich_effect X-ray_absorption ## X-ray_flare X-ray_flare D "X-ray flare" BT flare RT active_galaxy active_star ## X-ray_fluorescence X-ray_fluorescence D "X-ray fluorescence" BT fluorescence photoluminescence ## X-ray_identification X-ray_identification D "X-ray identification" RT X-ray_source optical_identification ## X-ray_line X-ray_line D "X-ray line" BT emission_line RT X-ray_spectrum ## X-ray_luminosity X-ray_luminosity D "X-ray luminosity" BT luminosity RT high-energy_radiation ## X-ray_map X-ray_map D "X-ray map" BT map RT X-ray_structure ## X-ray_nova X-ray_nova D "X-ray nova" BT nova RT X-ray_binary_star ## X-ray_observatory X-ray_observatory D "X-ray observatory" BT observatory space_observatory ## X-ray_polarization X-ray_polarization D "X-ray polarization" BT light_polarization RT polarized_radiation ## X-ray_pulsar X-ray_pulsar D "X-ray pulsar" BT pulsar NT HZ_Herculis_star RT X-ray_binary_star neutron_star white_dwarf ## X-ray_quasar X-ray_quasar D "X-ray quasar" BT quasar ## X-ray_radiation X-ray_radiation ALT "X-ray" D "X-ray radiation" BT electromagnetic_radiation high-energy_radiation radiation RT X-ray_background X-ray_scattering X-ray_source X-ray_spectrum CN "FVH: moved X-ray to here (2007-OCT-8)" ## X-ray_scattering X-ray_scattering D "X-ray scattering" BT radiation_scattering RT Compton_effect X-ray_diffraction X-ray_radiation ## X-ray_source X-ray_source D "X-ray source" BT source NT RS_Canum_Venaticorum_star X-ray_binary_star active_galactic_nucleus active_galaxy RT Seyfert_galaxy X-ray_identification X-ray_radiation X-ray_star eruptive_binary_star optical_identification quasar radio_galaxy relativistic_star supernova_remnant ## X-ray_spectrum X-ray_spectrum D "X-ray spectrum" NT X-ray_absorption X-ray_continuum X-ray_emission RT X-ray_line X-ray_radiation ## X-ray_spectrograph X-ray_spectrograph ALT "X-ray spectrometer" D "X-ray spectrograph" BT grazing_incidence_spectrograph spectrograph RT X-ray_astronomy ## X-ray_spectroscopy X-ray_spectroscopy D "X-ray spectroscopy" BT spectroscopy RT X-ray_diffraction ## X-ray_star X-ray_star D "X-ray star" BT active_star emission_line_star RT X-ray_binary_star X-ray_source radio_star ## X-ray_structure X-ray_structure D "X-ray structure" RT X-ray_map ## X-ray_survey X-ray_survey D "X-ray survey" BT survey ## X-ray_telescope X-ray_telescope D "X-ray telescope" BT grazing_incidence_telescope space_telescope RT X-ray_astronomy ## X-ray_transient X-ray_transient D "X-ray transient" RT X-ray_burst ## Yagi_antenna Yagi_antenna D "Yagi antenna" BT antenna directional_antenna radio_telescope RT half-wave_dipole ## y_array y_array D "y-array" BT array radio_interferometer RT t_array ## year year D "year" NT anomalistic_year cosmic_year tropical_year RT Universal_Time ephemeris_time light_year sidereal_time time ## Yerkes_classification Yerkes_classification D "Yerkes galaxy classification scheme" RT B_galaxy D_galaxy E_galaxy Ep_galaxy galaxy I_galaxy L_galaxy N_galaxy S_galaxy cD_galaxy HN "FVH: new (2007-OCT-12)" CN "FVH: removed NTs (2007-NOV-15)" ## yoke_mounting yoke_mounting D "yoke mounting" BT equatorial_mounting ## young_disk_Cepheid young_disk_Cepheid D "young disc Cepheid" UK "young disk Cepheid" BT Cepheid ## young_star_cluster young_star_cluster D "young star cluster" BT open_star_cluster RT OB_star T_association population_I_star young_star ## young_star young_star D "young star" BT population_I_star star NT B_star O_star OB_star blue_straggler_star pre-main_sequence_star RT H_II_region OB_association R_association T_association young_star_cluster N "only the broad classes are shown below; specific type will be found under these, or from the hierarchical list ## ytterbium ytterbium ALT "Yb" D "ytterbium (atomic number 70)" BT fundamental_chemical_element rare_earth HN "FVH: new (2007-OCT-25)" ## yttrium yttrium ALT "Y" D "yttrium (atomic number 39)" BT fundamental_chemical_element rare_earth HN "FVH: new (2007-OCT-25)" ## Z_Andromedae_star Z_Andromedae_star D "Z Andromedae star" BT close_binary_star emission_line_star shell_star symbiotic_star ## Z_Camelopardalis_star Z_Camelopardalis_star D "Z Camelopardalis star" BT dwarf_nova RT UX_Ursae_Majoris_star VY_Sculpturis_star ## Zeeman_splitting Zeeman_splitting ALT "line splitting" "spectral line splitting" D "Zeeman splitting" BT magneto-optical_effect RT Doppler_broadening Paschen-Back_effect Stark_broadening line_broadening line_shift natural_line_width pressure_broadening ## zenith_distance zenith_distance D "zenith distance" RT altitude_angle diurnal_parallax refraction_angle ## zenith_hourly_rate zenith_hourly_rate D "zenith hourly rate" RT meteor_shower ## zenith_telescope zenith_telescope D "zenith telescope" BT refracting_telescope transit_telescope NT zenith_tube RT meridian_observation CN "FVH: removed photographic_zenith_tube, moved zenith_tube to NT (2007-OCT-1)" ## zenith_tube zenith_tube ALT "photographic zenith tube" D "zenith tube" BT zenith_telescope ## zenith zenith D "zenith" BT pole RT celestial_sphere horizon_coordinate_system nadir ## zero-age_horizontal_branch zero-age_horizontal_branch D "zero-age horizontal branch" RT Hertzsprung-Russell_diagram giant_branch zero-age_main_sequence ## zero-age_main_sequence zero-age_main_sequence ALT "ZAMS" D "zero-age main sequence" RT Hertzsprung-Russell_diagram main_sequence zero-age_horizontal_branch ## zero_point zero_point D "zero point" N "combine with other terms" ## zinc zinc ALT "Zn" D "zinc (atomic number 30)" BT fundamental_chemical_element HN "FVH: new (2007-OCT-25)" ## zirconium_star zirconium_star D "zirconium star" RT S_star giant heavy_metal_star molecular_band zirconium ## zirconium zirconium ALT "Zr" D "zirconium (atomic number 40)" BT fundamental_chemical_element RT zirconium_star HN "FVH: new (2007-OCT-25)" ## zodiacal_dust_cloud zodiacal_dust_cloud D "zodiacal dust cloud" N "see zodiacal dust" ## zodiacal_dust zodiacal_dust D "zodiacal dust" BT dust RT gegenschein interplanetary_matter meteoroid_dust_cloud meteoroid zodiacal_light ## zodiacal_light zodiacal_light D "zodiacal light" RT F_corona gegenschein interplanetary_matter light_scattering night_sky_brightness radiation_scattering sky_brightness zodiacal_dust ## zodiac zodiac D "zodiac" RT Earth_orbit astrology constellation ecliptic ## zone_of_totality zone_of_totality D "zone of totality" RT solar_eclipse umbra ## ZZ_Ceti_star ZZ_Ceti_star D "ZZ Ceti star" BT multi-periodic_variable_star pulsating_variable_star white_dwarf RT He_II_ionization_zone kappa_mechanism non-radial_pulsation