All Classes (3955)
- Thing
- _21CmLine
- _53PerseiStar
- ABand
- AbellCluster
- AbellDistanceClass
- AbellRadius
- AbellRichnessClass
- aberration
- ablation
- abnormalSpectrum
- absoluteMagnitude
- absoluteMagnitudeInB
- absoluteMagnitudeInH
- absoluteMagnitudeInI
- absoluteMagnitudeInJ
- absoluteMagnitudeInK
- absoluteMagnitudeInR
- absoluteMagnitudeInU
- absoluteMagnitudeOfGalaxy
- absoluteTemperature
- absoluteTemperatureScale
- absoluteZero
- absorption
- absorptionCoefficient
- absorptionEdge
- absorptionLine
- absorptionLineSystem
- absorptionSpectroscopy
- absorptionSpectrum
- abstractFormat
- abundance
- abundanceRatio
- acceleration
- accelerationUnit
- accretion
- accretionDisk
- accumulationTheory
- accuracy
- achondrite
- acoustics
- acousticWave
- actinium
- activeGalacticNucleus
- activeGalacticNucleusGalaxy
- activeGalaxy
- activeOptics
- activeProminence
- activeRegion
- activeStar
- activityIndex
- acuteAngle
- adaption
- adaptiveOptics
- addition
- address
- adiabaticProcess
- adjustment
- adsorption
- ADwarf
- aerolite
- aeronomy
- AeStar
- afterglow
- age
- AGiant
- air
- airglow
- airplaneBorneInstrument
- airPollution
- AiryDisk
- albedo
- AlfvenSurface
- AlfvenWave
- algebra
- AlgolVariableStar
- algorithmOutput
- alignmentOptics
- allSkyCamera
- allSkyPhotography
- almanac
- alpha2CanumVenaticorumStar
- alphaParticle
- altazimuthMounting
- altimeter
- altimetry
- altitudeAngle
- aluminizing
- aluminum
- aluminumCoating
- amateurAstronomy
- AmCanumVenaticorumStar
- americium
- AmHerculisStar
- AmHerTypeStar
- ammonia
- amorGroup
- amountOfSubstanceUnit
- amplifier
- amplitude
- amplitude
- amplitudeOfVector
- AmStar
- analogRecorder
- analysis
- analysis
- anemometer
- angle
- angleDescription
- angleOfRotation
- angleUnit
- angularCoordinate
- angularDiameter
- angularMomentum
- angularRadius
- angularResolution
- angularSeparation
- angularSize
- angularVelocity
- angularVelocityUnit
- anisotropy
- anisotropy
- annualEquation
- annualParallax
- annularEclipse
- anomalousXRayPulsar
- anomaly
- ansa
- antapex
- antarcticObservatory
- antenna
- antennaDesign
- anthropicPrinciple
- anthropicPrinciple
- anthropocentrism
- anthropomorphism
- anticenter
- antimatter
- antimony
- antineutrino
- antinode
- antinucleon
- antiparticle
- antiproton
- antireflectionCoating
- any-D_Shape
- apastron
- aperiodicComet
- aperture
- aperturePhotometry
- apertureSynthesis
- apex
- aphelion
- apoapsis
- apodization
- apogee
- ApolloGroup
- apparentIntensity
- apparentIntensityInB
- apparentIntensityInH
- apparentIntensityInI
- apparentIntensityInJ
- apparentIntensityInK
- apparentIntensityInR
- apparentIntensityInU
- apparentIntensityInV
- apparentMagnitude
- apparentPosition
- apparentSuperluminalMotion
- apsidalMotion
- apsis
- ApStar
- arc
- archaeoastronomy
- archivist
- arcLength
- arcminute
- arcsecond
- area
- area
- areaUnit
- argon
- argumentOfThePerihelion
- AristotelianPhysics
- armillarySphere
- array
- arrayProcessor
- arsenic
- article
- artificialSatellite
- ascendingNode
- ashenLight
- AStar
- astatine
- asteroid
- asteroidBelt
- asteroidOccultation
- asteroseismology
- astigmatism
- astroBiology
- astrobiology
- astrodynamics
- astroEvent
- astrograph
- astrographicCamera
- astrographicCatalog
- astrolabe
- astroMatterObject
- astroMeasurement
- astrometricBinaryStar
- astrometricInstrument
- astrometry
- astronomer
- astronomicalCatalog
- astronomicalConstant
- astronomicalGeodesy
- astronomicalInstitution
- astronomicalOptics
- astronomicalResearch
- astronomicalSoftware
- astronomicalTechnique
- astronomy
- astronomyEntity
- astronomyTheory
- astroObject
- astrophysicist
- astrophysics
- astrophysics
- ASubdwarf
- ASubgiant
- ASupergiant
- asymptoticGiantBranch
- ataxite
- atlas
- atmosphere
- atmosphericDensity
- atmosphericExtinction
- atmosphericRadiation
- atmosphericRefraction
- atmosphericScattering
- atmosphericScintillation
- atmosphericTide
- atmosphericWindow
- atom
- atom
- atomicClock
- atomicConstant
- atomicElectronicState
- atomicIsotope
- atomicLine
- atomicMassConstant
- atomicMassUnit
- atomicNucleus
- atomicPhysics
- atomicProcess
- atomicSpectrum
- atomicTime
- attenuation
- aurora
- auroralArc
- auroralJet
- australite
- author
- autoCorrelation
- autoguider
- automatedTelescope
- automaticPatrolTelescope
- autumnalEquinox
- auxiliaryInstrument
- avalanchePhotodiode
- average
- AvogadroNumber
- axialRatio
- axion
- axis
- axis
- axis
- axisymmetricSystem
- axonometricProjection
- azimuth
- azimuthalAngle
- azimuthalQuantumNumber
- BaadeWesselinkMethod
- background
- backgroundNoise
- backgroundRadiation
- BahcallSoneiraModel
- BaileyType
- BailysBead
- BakerNunnCamera
- BallikRamsayBand
- balloonBorneInstrument
- BalmerContinuum
- BalmerJump
- BalmerLimit
- BalmerLine
- BalmerSeries
- bandHead
- barium
- bariumStar
- barometer
- barredSpiralGalaxy
- baryon
- baryonicDarkMatter
- baseUnit
- basin
- BBand
- BBand
- BDwarf
- beamSwitching
- beamWaveguide
- beamwidth
- bediasite
- berkelium
- BernoulliEquation
- beryllium
- BesselianElement
- BesselianEpoch
- BesselianYear
- BesselPhotometry
- BeStar
- betaCepheiStar
- BetaCepTypeStar
- betaLyraeStar
- BGalaxy
- BGiant
- BianchiCosmology
- biasCalibration
- biasedGalaxyFormation
- bigBang
- bigBangTheory
- bigCrunch
- binaryOperation
- binaryPulsar
- binaryStar
- binarySystem
- bindingEnergy
- biologist
- biology
- bipolarGalaxy
- bipolarGroup
- bipolarNebula
- bipolarOutflow
- birthRate
- bismuth
- blackBodyFit
- blackBodyRadiation
- blackDwarf
- blackHole
- blankField
- blazar
- BlazhkoEffect
- BlHerculisStar
- bLines
- blinkComparator
- blinking
- BlLac
- blueGalaxy
- blueLoop
- blueObject
- blueshift
- blueStragglerStar
- BMagnitude
- BodesLaw
- BohrAtom
- bohrium
- BohrMagneton
- BokGlobule
- bolide
- bolometer
- bolometricAbsoluteMagnitude
- bolometricCorrection
- BoltzmannConstant
- book
- boron
- BoseEinsteinCondensate
- BoseEinsteinStatistics
- boson
- bosonicStringTheory
- bottomQuark
- bottomupScenario
- boundary
- boundaryLayer
- boundFreeTransition
- BouwersTelescope
- bowShock
- BpStar
- BrackettLine
- BrackettSeries
- BraggAngle
- BrAlpha
- brane
- bremsstrahlung
- bridge
- brightGalaxy
- brightNebula
- brightness
- brightness
- brightnessDistribution
- brightnessTemperature
- brightStar
- brillouinScattering
- brillouinSpectrum
- broadAbsorptionLineQSO
- broadAbsorptionLineSystem
- broadBandPhotometry
- bromine
- brownDwarf
- BStar
- BSubdwarf
- BSupergiant
- bubble
- BurkertProfile
- burningZone
- burst
- burster
- BwStar
- ByDraconisStar
- C2Band
- cabinetProjection
- cadmium
- caesium
- CaHLine
- CaIiEmissionLine
- CaKLine
- calcium
- calciumLine
- calculation
- calculus
- calculusOfVariation
- calendar
- calendarYear
- calibration
- californium
- camera
- cameraLens
- canyon
- capacitance
- capacitanceUnit
- CapePhotometry
- CapeRiPhotometry
- capture
- carbon
- carbonaceousChondrite
- carbonBurning
- carbonCompound
- carbonDetonationSupernovaModel
- carbonDioxide
- carbonDisulfide
- carbonFlash
- carbonLine
- carbonMonosulfide
- carbonMonoxide
- carbonNitrogenCycle
- carbonStar
- CartesianCoordinate
- CartesianCoordinateSystem
- CassegrainAntenna
- CassegrainFocus
- CassegrainTelescope
- cataclysmicVariableEruption
- cataclysmicVariableStar
- catadioptricSystem
- catalog
- catastropheTheory
- cathode
- catoptricSystem
- causality
- cause
- caustic
- causticCrossing
- cavalierProjection
- CcdDetector
- CcdObservation
- CcdPhotometry
- cDGalaxy
- celestialCoordinateSystem
- celestialMechanics
- celestialPole
- celestialSphere
- celsiusTemperatureScale
- center
- center
- centerOfMass
- centerOfMass
- centerOfRotation
- centigrade
- centralAngleOfCircle
- centrallyDirectedForce
- centralStar
- centrifugalForce
- centripetalForce
- Cepheid
- CepheidDistance
- CepheidStar
- CerenkovCounter
- CerenkovRadiation
- Ceres
- cerium
- CgsUnit
- cgsUnit
- ChandlerWobble
- ChandrasekharLimit
- ChandrasekharSchoenbergLimit
- chapter
- chargeCoupledDevice
- chargeInjectionDevice
- chargeTransferDevice
- chargeUnit
- charmQuark
- chemicalAbundance
- chemicalComposition
- chemicalCompound
- chemicalElement
- chemicalEquilibrium
- chemicalEvolution
- chemicalEvolution
- chemicalMixture
- chemicalSubstance
- chemiluminescence
- chemist
- chemistry
- chemistry
- ChGBand
- chlorine
- chondrite
- chondrules
- chord
- chromaticAberration
- chromium
- chromosphere
- chronometer
- ChStar
- CIEmission
- CIiRegion
- circle
- circularCone
- circularOrbit
- circularPolarization
- circumference
- circumplanetaryMatter
- circumstellarDisk
- circumstellarDust
- circumstellarEnvelope
- circumstellarGas
- circumstellarGrain
- circumstellarMatter
- circumstellarShell
- civilTime
- classicalElectronRadius
- classicalNova
- classicalPhysics
- classicalTTauriStar
- classicCepheidStar
- classification
- cleanMethod
- clock
- closeBinaryStar
- closedCurve
- closedString
- closedUniverse
- closeEncounter
- cloud
- cloudMonitor
- clumping
- cluster
- cluster
- clustering
- CnoAnomaly
- CnStar
- coating
- coating
- cobalt
- cocoonStar
- coefficient
- coelostat
- coherence
- coInvestigator
- coldDarkMatter
- collapse
- collapsedStar
- collapsingCloud
- Collection
- collimation
- collimator
- collision
- collision
- collisionalExcitation
- collisionalPlasma
- collisionBroadening
- collisionlessBoltzmannEquation
- collisionProcess
- collisionStrength
- color
- color
- colorEquation
- colorExcess
- colorimetry
- colorIndex
- colorLuminosityRelation
- colorMagnitudeRelation
- colorPhotography
- colorRedshiftRelation
- colorTemperature
- colorVision
- coma
- comaticAberration
- comet
- cometaryGlobule
- commensurateOrbit
- compactGalaxy
- compactGroup
- compactHIiRegion
- compactNebula
- compactNucleus
- compactObject
- compactSource
- companionGalaxy
- companionStar
- comparison
- comparisonLamp
- comparisonStar
- compiledProgram
- component
- component
- compositeParticle
- compositeQuantity
- composition
- ComptonEffect
- ComptonScattering
- ComptonWavelength
- computer
- computerApplication
- computerLanguage
- computerModel
- computerProgram
- computerSimulation
- computing
- concavePolygon
- concentrationUnit
- Concept
- concept
- ConceptScheme
- condensation
- conductance
- conductanceQuantum
- conductanceUnit
- conduction
- cone
- conicSection
- conjunction
- conservationLaw
- consistent
- constant
- constellation
- contactBinaryStar
- continent
- continentalDrift
- continuousSpectrum
- continuumRadiation
- contourMap
- contraction
- contrast
- controlSystem
- convection
- convectionZone
- convectiveEnvelope
- convectiveShell
- convectiveZone
- convexPolygon
- cooling
- coolingFlow
- coordinate
- coordinatedUniversalTime
- coordinates
- coordinateSystem
- coordinateTransformation
- CopenhagenInterpretation
- copper
- core
- core
- coreRadius
- corona
- coronagraph
- coronalDimming
- coronalGreenLine
- coronalHole
- coronalLine
- coronalLoop
- coronalMassEjection
- coronalPlume
- coronalTransient
- coronalWave
- corpuscularEmission
- correction
- correction
- correctionForInterveningMatter
- correctionForObscuration
- correctionForProjection
- correctionForTimeDelay
- correctorPlate
- correlation
- correlation
- cosmic
- cosmicAbundance
- cosmicBackgroundRadiation
- cosmicElectrodynamics
- cosmicMatterDensity
- cosmicNoise
- cosmicRay
- cosmicRayAstronomy
- cosmicRayShower
- cosmicRaySource
- cosmicString
- cosmicYear
- cosmochemistry
- cosmochronology
- cosmogony
- cosmologicalConstant
- cosmologicalDistanceScale
- cosmologicalModel
- cosmologicalParameter
- cosmology
- CoudeFocus
- CoudeSpectrograph
- CoudeSpectrum
- CoulombForce
- counter
- counting
- coupledEquations
- coupling
- CPTInvariance
- CPViolation
- crater
- creation
- creationEvent
- creator
- criticalDensity
- crossCorrelation
- crossingTime
- crossSection
- crossSection
- crosssection
- crust
- crustalDynamics
- cryogenics
- cryostat
- Cs
- CsStar
- cube
- curium
- current
- currentDensity
- currentDensityUnit
- currentSheet
- currentUnit
- curve
- curveOfGrowth
- curveOnPlane
- cusp
- cuspCrossing
- cyanoacetylene
- cyanodiacetylene
- cyanogen
- cyanogenBand
- cyanogenLine
- cyanopolyene
- cycle
- cyclotronRadiation
- cylindricalCoordinateSystem
- cylindricalRadialCoordinate
- cylindricalRadius
- D1Line
- D2Line
- dampedLymanAlphaAbsorptionSystem
- dampingConstant
- DanjonAstrolabe
- darkAdaption
- darkCloud
- darkCurrentCalibration
- darkEnergy
- darkMatter
- darkMatterHalo
- darkNebula
- darkness
- darkroom
- darlyTypeGalaxy
- darmtadtium
- DaStar
- dataAcquisition
- dataAnalysis
- database
- dataCenter
- dataCollection
- dataFormat
- dataProcessing
- dataReduction
- dataRetrieval
- dataStandard
- dataStorage
- dateInterval
- DbStar
- DDOClass
- DdoPhotometry
- deadTimeCalibration
- decayOscillation
- deceleration
- decelerationParameter
- declination
- deconvolution
- deduction
- defect
- deformation
- degeneracyPressure
- degenerateDwarf
- degenerateMatter
- degenerateStar
- delayTime
- deltaDelphiniStar
- deltaScutiStar
- denseCloud
- densitometer
- densitometry
- density
- density
- densityBounded
- densityDistribution
- densityFluctuation
- densityPerturbation
- densityVariation
- densityWaveModel
- depth
- derivation
- derivativeTypeCode
- descendingNode
- design
- deSitterUniverse
- destruction
- detachedBinaryStar
- detection
- detection
- detector
- detectorArray
- determination
- determinism
- deuterium
- deVaucouleursType
- DGalaxy
- diagonal
- diagonalLength
- diagram
- diameter
- diameter
- diamondRingEffect
- dichroicMirror
- DickeRadiometer
- difference
- differentialEquation
- differentialEquations
- differentialImageMotionMonitor
- differentialRotation
- diffraction
- diffractionGrating
- diffractionPatterns
- diffuseNebula
- diffuseRadiation
- diffusion
- digitalImage
- digitalRecorder
- dilation
- dimension
- diode
- diodeArray
- dioptricSystem
- dipole
- dipoleAntenna
- dipoleStrength
- diracCosmology
- directedGraph
- direction
- directionalAntenna
- directPairGravityCalculation
- directrix
- dirtySnowballTheory
- discoloration
- discoverer
- discovery
- discreteParticleCode
- discreteRadioSource
- dishAntenna
- disintegration
- disk
- diskFlaring
- diskGalaxy
- diskOfGalaxy
- diskPopulation
- diskStar
- dispersion
- dispersionUnit
- disruption
- dissipation
- distance
- distanceIndicator
- distanceModulus
- distanceScale
- distortion
- distributionFunction
- distributionInSpace
- diurnalParallax
- diurnalPhenomena
- diurnalVariation
- division
- DLayer
- DLine
- Document
- dome
- domeSeeing
- DopplerBroadening
- DopplerEffect
- DoStar
- doubleGalaxy
- doubleModeCepheid
- doubleModePulsation
- doubleModeVariableStar
- doubleQuasar
- doublet
- downQuark
- DqHerculisStar
- dredgeUp
- driftScan
- driftWave
- drive
- dubnium
- duration
- dust
- dustCloud
- dustDetector
- dustGrain
- dustNebula
- dustShell
- dustStorm
- dwarf
- dwarfCepheid
- dwarfElliptical
- dwarfGalaxy
- dwarfIrregular
- dwarfNova
- dwarfPlanet
- dwarfSpheroidalGalaxy
- dynamicalEvolution
- dynamicalFriction
- dynamicalParallax
- dynamicalTime
- dynamics
- dynamicsCode
- dynamoTheory
- dysprosium
- earlyTypeEmissionStar
- earlyTypeGalaxy
- earlyTypeStar
- earlyTypeSupergiant
- earlyTypeVariableStar
- earlyUniverse
- EarthMoonSystem
- EarthOrbit
- earthquake
- EarthRotation
- EarthScience
- Earthshine
- eastPoint
- eccentricAnomaly
- eccentricity
- eccentricity
- echelleGrating
- echelleSpectrograph
- echelleSpectrum
- eclipse
- eclipseYear
- eclipsingBinaryStar
- ecliptic
- eclipticCoordinateComponent
- eclipticCoordinates
- eclipticCoordinateSystem
- eclipticLatitude
- eclipticLongitude
- eclipticPlane
- eclipticPole
- ECorona
- EddingtonApproximation
- EddingtonLemaitreUniverse
- EddingtonLimit
- edge
- edgeEffect
- EdgeworthKuiperBelt
- EdgeworthKuiperBeltObject
- editor
- effectiveTemperature
- eFoldingTime
- EGalaxy
- EinsteinCoefficient
- EinsteinEffect
- einsteinium
- EinsteinRing
- EinsteinUniverse
- ejecta
- ejection
- elasticity
- ELayer
- electricalProperty
- electricalUnit
- electricCharge
- electricCurrent
- electricDipole
- electricDipoleStrength
- electricField
- electricity
- electricPotential
- electricPotentialUnit
- electrode
- electrodynamics
- electromagnetic
- electromagneticConstant
- electromagneticGaugeSymmetry
- electromagneticLaw
- electromagneticQuantity
- electroMagnetics
- electromagneticUnit
- electron
- electronBeam
- electronComptonWavelength
- electronDensity
- electronGFactor
- electronGyromagneticRatio
- electronicCamera
- electronicEquipment
- electronics
- electronicState
- electronicTransition
- electronMagneticMoment
- electronMagneticMomentAnomaly
- electronNeutrino
- electronographicCamera
- electronPumping
- electronTemperature
- electronTemperature
- electrostaticWave
- elementaryCharge
- elementaryParticle
- elementaryParticleScattering
- elementFormation
- elevation
- elevenDimensionalSupergravity
- ELine
- ellipse
- ellipsoidalVariableStar
- ellipticalGalaxy
- ellipticalOrbit
- elongation
- EmAbsorption
- EmEmission
- emergingFlux
- EmField
- EmForce
- EmInteraction
- emission
- emissionCoefficient
- emissionLine
- emissionLineGalaxy
- emissionLineObject
- emissionLineStar
- emissionNebula
- emissionSpectrum
- emissivity
- empiricism
- EmRadiation
- EmTheory
- encounter
- endPoint
- energeticParticle
- energy
- energyContent
- energyDensity
- energyDistribution
- energyLevel
- energySource
- energySpectrum
- energyTransfer
- energyUnit
- engineering
- EnglishMounting
- enrichment
- enthalpy
- entropy
- envelope
- eon
- EpGalaxy
- ephemeralActiveRegion
- ephemeris
- ephemerisTime
- epicycle
- epoch
- epoch
- eProcess
- equation
- equationOfState
- equationOfTheCenter
- equationOfTheEquinox
- equationOfTime
- equator
- equator
- equatorCorrection
- equatorDetermination
- equatorialBulge
- equatorialCoordinate
- equatorialCoordinateComponent
- equatorialCoordinates
- equatorialCoordinateSystem
- equatorialMounting
- equatorialPlane
- equatorialSystem
- equatorialZone
- equatorPosition
- equilateralTriangle
- equilibrium
- equilibriumFigure
- equinox
- equinoxCorrection
- equinoxPosition
- equipotentialSurface
- equivalentWidth
- erbium
- eRegion
- ergosphere
- erosion
- erratum
- error
- error
- errorAnalysis
- eruption
- eruptiveBinaryStar
- escapeVelocity
- ethane
- ethylene
- EulerEquation
- EulerianDerivativeCode
- europium
- evaporation
- event
- eventHorizon
- EvershedEffect
- evolution
- evolutionaryTrack
- evolvedStar
- exactRelationship
- excitation
- excitationPotential
- excitingStar
- exclusionPrinciple
- exoSolarPlanet
- exosphere
- expandingEnvelope
- expandingUniverse
- expansion
- experiment
- explosion
- explosion
- exponentialProfile
- expression
- extendedObject
- extendedSource
- extragalacticAstronomy
- extragalacticObject
- extragalacticRadioSource
- extrasolarPlanet
- extraterrestrialIntelligence
- extraterrestrialLife
- extremeCarbonStar
- extremeHorizontalBranchStar
- extremePopulationIStar
- extremeUltravioletRadiation
- eyepiece
- FaberJacksonDistance
- FaberJacksonRelation
- FabryPerotInterferometer
- FabryPerotSpectrograph
- face
- facula
- faintBlueStar
- faintGalaxy
- faintStar
- falseColorPhotography
- FaradayConstant
- FaradayEffect
- farInfraredRadiation
- farUltravioletRadiation
- fastFourierTransform
- fastNova
- FCorona
- FDwarf
- feed
- feedHorn
- FermiCouplingConstant
- FermiDiracSommerfeldLaw
- FermiDiracStatistics
- FermiInteraction
- FermiLevel
- fermion
- FermionicCondensate
- fermium
- FeynmanDiagram
- FeynmanIntegral
- FGiant
- fiberOptics
- fibrill
- field
- fieldCorrector
- fieldCurvature
- fieldEquation
- fieldGalaxy
- FieldOfOptics
- fieldOfStudy
- fieldOfView
- fieldStar
- figuring
- filamentaryNebula
- fileLocation
- fileLocation
- fillingFactor
- filter
- filterWheel
- findingChart
- findingList
- fineAnalysis
- fineStructure
- fineStructureConstant
- fineTuning
- fireball
- firstOrderDifferentialEquation
- firstOrderPerturbationAnalysis
- fission
- fiveMinuteOscillations
- FkCatalogSystem
- flare
- flareStar
- flashSpectrum
- flashStar
- flatField
- flatFieldLamp
- flatnessProblem
- flattening
- flatUniverse
- flavor
- fLayer
- flexure
- float
- floatFormat
- FloquetAnalysis
- florine
- flow
- flow
- flowInstability
- fluctuation
- fluidDynamics
- fluidFlow
- fluidMechanics
- fluorescence
- flux
- flux
- fluxDensity
- focalLength
- focalReducer
- focus
- focusPoint
- FokkerPlanckEquation
- FokkerPlanckEquation
- forbiddenLine
- forbiddenTransition
- forbushEffect
- force
- force
- forceUnit
- forecasts
- forkMounting
- formation
- FourierAnalysis
- FourierComponent
- FourierSpectrograph
- FourierTransform
- FourierTransformGravityCalculation
- FourierTransformSpectroscopy
- fractal
- fragment
- fragmentation
- francium
- FraunhoferLine
- freeBoundEmission
- freeFreeEmission
- FreemanBar
- freeParameter
- fRegion
- frequency
- frequency
- frequencyAnalysis
- frequencyDistribution
- frequencyShift
- frequencyStandard
- frequencyUnit
- friction
- FriedmannUniverse
- frozenInElement
- FStar
- FSubdwarf
- FSubgiant
- FSupergiant
- function
- fundamentalChemicalElement
- fundamentalFrequency
- fundamentalMode
- fundamentalParticle
- fundamentalPlane
- fundamentalStar
- fundamentalSystem
- funneling
- FuOrionisStar
- fusion
- futureLightCone
- gadolinium
- galactic
- GalacticAnticenter
- GalacticAstronomy
- GalacticCluster
- GalacticCoordinate
- GalacticCoordinateComponent
- GalacticCoordinates
- GalacticCoordinateSystem
- GalacticCosmicRay
- GalacticCylindricalCoordinateSystem
- GalacticDynamics
- GalacticLatitude
- GalacticLongitude
- GalacticNucleus
- GalacticPole
- GalacticRotation
- GalacticSpurs
- GalacticStructure
- GalacticWindow
- GalacticZcoordinate
- GalactocentricDistance
- galaxy
- galaxyAxialRatio
- galaxyAxialRatioIntrinsic
- galaxyBar
- galaxyBulge
- galaxyBulgeToDiskRatio
- galaxyCatalog
- galaxyCenter
- galaxyCluster
- galaxyClusterAffiliation
- galaxyContent
- galaxyCount
- galaxyDiskThickness
- galaxyDistribution
- galaxyEncounter
- galaxyEvolution
- galaxyFormation
- galaxyGlobalLineWidth
- galaxyGroup
- galaxyHalo
- galaxyHiLineWidth
- galaxyHiMassFraction
- galaxyInternalReddening
- galaxyMassToLightRatio
- galaxyMeasurement
- galaxyMerger
- galaxyMorphologyType
- GalaxyMorphologyType
- galaxyNucleus
- galaxyPair
- galaxyPart
- galaxyRotation
- galaxyRotationCurve
- galaxySimulation
- galaxyStructure
- galaxyTheory
- galaxyVoid
- galileanSatellite
- GalileanTransformation
- gallium
- gammaCassiopeiaeStar
- gammaDorTypeStar
- gammaRayAstronomy
- gammaRayBackground
- gammaRayBurst
- gammaRayLine
- gammaRayObservatory
- gammaRayRadiation
- gammaRayScattering
- gammaRaySource
- gammaRaySpectrograph
- gammaRaySpectroscopy
- gammaRaySpectrum
- gammaRayTelescope
- gas
- gas
- gasCloud
- gasContent
- gasDistribution
- gasDynamics
- gaseousDisk
- gaseousNebula
- gaseousNebulaCatalog
- gaseousSphere
- gasLaw
- gasToDustRatio
- gaugeSymmetry
- gaugeTheory
- Gaussian
- GaussianYear
- GBand
- GDwarf
- gegenschein
- generalAstroMeasurement
- generalRelativity
- generalTheoryOfRelativity
- GenevaPhotometry
- geocentricCoordinate
- geocentricCoordinateComponent
- geocentricCosmology
- geocentricOrbit
- geocorona
- geodesy
- geodeticPosition
- geoid
- geology
- geomagneticField
- geomagnetism
- geometricalObject
- geometricCenter
- geometricEntity
- geometry
- geophysicalObservatory
- geophysicist
- geophysics
- geostationarySatellite
- germanium
- GermanMounting
- GFactor
- gfValue
- GGiant
- giantBranch
- giantBranchStar
- giantEllipticalGalaxy
- giantGalaxy
- giantMolecularCloud
- giantPlanet
- giantRadioGalaxy
- giantStar
- glaciology
- glass
- GLAT
- glitch
- globalInertialFrame
- globalPositioningSystem
- globularCluster
- globularClusterCatalog
- globule
- GLON
- gluon
- GoedelUniverse
- gold
- GouldsBelt
- gradient
- gradingFunction
- grandUnifiedTheory
- granulation
- granule
- graph
- graphite
- graticule
- gratingResponse
- gratingRing
- gratingSpectrograph
- gravimetry
- gravitatingDisk
- gravitation
- gravitationalCollapse
- gravitationalConstant
- gravitationalDeflection
- gravitationalEffect
- gravitationalEnergy
- gravitationalEquilibrium
- gravitationalField
- gravitationalForce
- gravitationalHorizon
- gravitationalImage
- gravitationalInstability
- gravitationalInteraction
- gravitationalLens
- gravitationalLensingShear
- gravitationalLensPart
- gravitationalLensSystem
- gravitationallyLensedSource
- gravitationalMass
- gravitationalMicrolens
- gravitationalPotentialEnergy
- gravitationalRadiation
- gravitationalRadius
- gravitationalRedshift
- gravitationalSource
- gravitationalWave
- graviton
- gravity
- gravity
- gravityAnomaly
- gravityDarkening
- gravityLaw
- gravityWave
- grazingIncidence
- grazingIncidenceSpectrograph
- grazingIncidenceTelescope
- greatCircle
- greatestElongation
- greenhouseEffect
- GregorianCalendar
- GregorianTelescope
- grid
- grism
- groundBasedAstronomy
- groundState
- GStar
- GSubdwarf
- GSubgiant
- GSupergiant
- guideSystem
- GunnDiode
- GunnPhotometry
- gValue
- gyrofrequency
- gyromagneticRatio
- gyrosynchrotronRadiation
- hadron
- hadronBarrier
- hafnium
- halation
- halfLife
- halfWaveDipole
- halfWavePlate
- halo
- haloStar
- HAlpha
- HAlphaEmissionLineStar
- HAlphaPhotometry
- HamiltonianEquation
- HAndKLine
- HanleEffect
- HarmanSeatonSequence
- harmonicFrequency
- harmonicOvertone
- harmonicRadius
- harmonograph
- HaroGalaxy
- HartmannTest
- HartreeEnergy
- hassium
- HawkingRadiation
- HayashiTrack
- HBeta
- HBetaPhotometry
- HdCurve
- HDelta
- headTailGalaxy
- heatTransfer
- heatUnit
- heavyElement
- heavyMetalStar
- HeI
- height
- height
- HeIi
- HeIii
- HeIiIonizationZone
- HeiiLymanAlpha
- heliocentricCorrection
- heliocentricJulianDate
- heliocentricOrbit
- heliocentricVelocity
- heliograph
- heliometer
- heliopause
- helioseismology
- heliosphere
- heliostat
- helium
- heliumBurning
- HeliumDiscontinuity
- heliumFlash
- heliumPoorStar
- heliumProblem
- heliumRichStar
- heliumShellFlash
- HelmholtzKelvinContraction
- HenryDraperSystem
- HenyeyTrack
- HEpsilon
- HerbigAeBeStar
- HerbigHaroObject
- HertzsprungGap
- HertzsprungRussellDiagram
- HessDiagram
- heterodyne
- heteroticEStringTheory
- heteroticOStringTheory
- heteroticStringTheory
- hexagon
- HGamma
- HIAbsorption
- HicksonCompactGroup
- HICloud
- HIContent
- HIEmission
- hierarchicalCosmology
- highEnergyAstrophysics
- highEnergyPhysics
- highEnergyPhysicsInstitution
- highEnergyRadiation
- higherDimensionalSupergravity
- highLuminosityStar
- highMassStar
- highMassXRayBinaryStar
- highResolutionSpectrosopy
- highResolutionSpectrum
- highSpeedPhotometer
- highState
- highTemperature
- highVelocityCloud
- highVelocityStar
- HIi
- HIiRegion
- HirayamaFamily
- HiRegion
- HIRegion
- HIShell
- history
- historyOfAstronomy
- HKLine
- HLine
- HMagnitude
- HolmbergRadius
- holmium
- holmiumStar
- HoltsmarkApproximation
- homogeneousEquation
- horizon
- horizonCoordinateSystem
- horizonProblem
- horizontalBranchStar
- horizontalParallax
- hornAntenna
- horseshoeMounting
- hourAngle
- HoyleNarlikarTheory
- HstPhotometry
- HubbleClass
- HubbleClassification
- HubbleConstant
- HubbleDiagram
- HubbleLaw
- HubbleRadius
- HubbleSandageVariableStar
- HubbleSpaceTelescope
- HubbleTime
- humanEvent
- hydratedCarbon
- hydrocarbon
- hydrodynamics
- hydrodynamics
- hydrogen
- hydrogenBurning
- hydrogenDeficientStar
- hydrogenLine
- hydrogenSpectralFeature
- hydrogenSpectrum
- hydrostaticEquilibrium
- hydrostatics
- hydroxylRadical
- hyperbola
- hyperbolicOrbit
- hyperboloid
- hyperfineLine
- hypergalaxy
- hypergiant
- hypernova
- hypothesis
- HzHerculisStar
- IBand
- identification
- IGalaxy
- illumination
- image
- Image
- Image
- imageProcessing
- imageReconstruction
- imageTube
- imagingInstrument
- IMagnitude
- ImfAxis
- ImfExponent
- ImfFit
- impactCrater
- impedance
- impedanceOfFreeSpace
- impersonalAstrolabe
- inclination
- incompressibleBernoulliEquation
- index
- indium
- indochinite
- inductance
- inductanceUnit
- induction
- inertialCoordinateSystem
- inertialReferenceFrame
- inflationaryUniverse
- infrared
- infraredAstronomy
- infraredDetector
- infraredEmission
- infraredGalaxy
- infraredObservatory
- infraredPhotometry
- infraredRadiation
- infraredRadiation
- infraredSource
- infraredTelescope
- infraredTransmissionWindow
- inhomogenity
- initialMassFunction
- innerCore
- innerLagrangianPoint
- innerPlanet
- instability
- instabilityStrip
- institution
- instrument
- instrumentalProfile
- integer
- integer
- integerFormat
- integralFieldSpectrograph
- integratedMagnitude
- integrationTime
- intensity
- intensityInterferometer
- interactingBinaryStar
- interactingGalaxies
- interactingGalaxy
- interaction
- interaction
- interArmRegion
- intercept
- intercloudGas
- intercloudMatter
- intercombinationLine
- interferenceFilter
- interferenceFringe
- interferenceNoise
- interferenceSpectrosocopy
- interferenceWave
- interferometer
- interferometricCorrelation
- interferometry
- intergalacticAbsorption
- intergalacticCloud
- intergalacticGas
- intergalacticMatter
- intergalacticSpace
- interior
- intermediateMassXRayBinaryStar
- intermediatePopulationStar
- intermediateTypeStar
- internalMotion
- internalSymmetry
- interplanetaryDust
- interplanetaryGas
- interplanetaryGrain
- interplanetaryMagneticField
- interplanetaryMatter
- interplanetaryScintillation
- interplanetarySpace
- intersection
- interstellarAbsorption
- interstellarBand
- interstellarBubble
- interstellarCloud
- interstellarCommunication
- interstellarDust
- interstellarGas
- interstellarLine
- interstellarMagneticField
- interstellarMatter
- interstellarMolecule
- interstellarReddening
- interstellarScintillation
- interstellarSpace
- interstellarWind
- interval
- intraclusterMatter
- intraClusterSpace
- intrinsicColor
- intrinsicVariableStar
- invariablePlane
- invention
- inventor
- inverseAngle
- inverseArea
- inverseComptonEffect
- inverseComptonScattering
- inverseLength
- inverseMaser
- inverseMassUnit
- inversePCygniLine
- inverseTimeUnit
- inverseVolumeUnit
- iodine
- iodineCell
- ion
- ionComposition
- ionDensity
- ionization
- ionizationEquilibrium
- ionizationPotential
- ionizedGas
- ionizingShockWave
- ionosphere
- ionosphericScintillation
- ionPlasmaWave
- ionTemperature
- IrasGalaxy
- IrasSatellite
- iridium
- iron
- ironMeteorite
- irradiance
- irrational
- irregularGalaxy
- irregularVariableStar
- isometric
- isophotalAngularDiameter
- isophotalAngularRadius
- isophotalDiameter
- isophotalRadius
- isophote
- isoplanaticPatch
- isoscelesTriangle
- isothermalSphere
- isothermalSphere
- IsoTime
- isotope
- isotopicAbundance
- isotopicComposition
- isotropy
- JacobiEllipsoid
- JdTime
- jeansEquation
- JeansLength
- JeansMass
- jet
- JMagnitude
- JohnsonBand
- JohnsonNoise
- JohnsonPhotometry
- JosephsonConstant
- journal
- jovianPlanet
- JulianCalendar
- JulianDate
- JulianEpoch
- JulianYear
- jumpCondition
- KalnajsDisk
- KaluzaKleinTheory
- KAM_Theory
- kappaMechanism
- KapteynSelectedArea
- KapteynUniverse
- KCorona
- kCorrection
- KDwarf
- KEdge
- KellnerEyepiece
- KelvinTimescale
- KeplerForceLaw
- KeplerianOrbit
- KeplersLaw
- KerrBlackHole
- KGiant
- KIDoublet
- kinematicParallax
- kinematics
- kineticEnergy
- kineticTemperature
- KingModel
- KirchhoffsLaw
- KirkwoodGap
- KleinAlfvenCosmology
- kLine
- KLine
- KMagnitude
- KramersOpacity
- KreutzSungrazer
- KronCousinsPhotometry
- KruskalDiagram
- krypton
- KStar
- KSubdwarf
- KSubgiant
- KSupergiant
- KuiperBand
- L1
- L2
- L3
- L4
- L5
- LagrangianDerivativeCode
- LagrangianEquation
- LagrangianPoint
- lambdaDoublet
- lambdaEridaniStar
- lamp
- lanthanum
- LaplaceSeries
- largeScaleStructure
- LarmorFrequency
- LarmorRadius
- laser
- laserRanging
- laserRanging
- lateTypeDwarf
- lateTypeGalaxy
- lateTypeGiant
- lateTypeStar
- lateTypeSubdwarf
- lateTypeSupergiant
- lateTypeVariableStar
- latitude
- latitudeAngle
- latitudeDetermination
- latitudeVariation
- lawrencium
- LbVariableStar
- LcVariableStar
- LDwarf
- lead
- LegendreExpansion
- LemaitreUniverse
- length
- length
- lengthUnit
- lens
- lensAntenna
- lensDesign
- lenticularGalaxy
- lepton
- LGalaxy
- libration
- librationOrbit
- life
- lifetime
- lightAbsorption
- lightAbsorption
- lightCoherence
- lightCone
- lightCurve
- lightEmission
- lightEmission
- lightInterference
- lightPolarization
- lightPollution
- lightScattering
- lightYear
- limbBrightening
- limbDarkening
- limitingMagnitude
- line
- linearCoordinateSystem
- linearityCalibration
- linearMassDensityUnit
- linearVelocityUnit
- lineBlanketing
- lineBlending
- lineBlocking
- lineBroadening
- lineCenter
- lineFormation
- lineIdentification
- lineIntensity
- lineOfApsides
- lineOfNodes
- lineOfSight
- lineParameter
- lineProfile
- liner
- lineRatio
- linerGalaxy
- lineSegment
- lineShift
- lineSpectrum
- lineWidth
- liquid
- LissajousCurve
- List
- lithium
- lithiumPoorStar
- lithiumStar
- lithosphere
- LMagnitude
- lobe
- localCoordinate
- localCoordinates
- localCoordinateSystem
- localHypothesisOfQuasars
- localInertialFrame
- LocalStandardOfRest
- localThermodynamicEquilibrium
- location
- locationBehind
- locationBetween
- locationInFront
- logarithm
- logGValue
- longBaselineInterferometer
- longBaselineInterferometry
- longitude
- longitudeAngle
- longitudeOfTheAscendingNode
- longPeriodComet
- longPeriodVariableStar
- longSlit
- longSlitSpectrum
- lookbackTime
- loop
- LorentzInvariance
- LorentzTransformation
- LoschmidtConstant
- loweredIsothermalModel
- lowLuminosityStar
- lowMassStar
- lowMassXRayBinaryStar
- lowState
- lowTemperaturePlasma
- LStar
- LSubdwarf
- luminanceUnit
- luminescence
- luminosity
- luminosity
- luminosityClass
- luminosityClassification
- luminosityDispersionRelation
- luminosityDistribution
- luminosityFunction
- luminousArc
- luminousBlueVariableStar
- luminousIntensityUnit
- luminousMass
- lunar
- lunarDome
- lunarEclipse
- lunarLaserRanging
- lunarOccultation
- lunarPhase
- lunarTheory
- lutetium
- LymanAlpha
- LymanAlphaAbsorptionSystem
- LymanAlphaForest
- LymanBeta
- LymanContinuum
- LymanLimitAbsorptionLineSystem
- LymanLine
- LymanSeries
- MachsPrinciple
- MaclaurinSpheroid
- macroSpicule
- macroturbulence
- MAddition
- MagellanicCloud
- MagellanicStream
- magnesium
- magnetar
- magneticAnomaly
- magneticConstant
- magneticDipoleStrength
- magneticDisturbance
- magneticField
- magneticFieldIntensityUnit
- magneticFlux
- magneticFluxDensity
- magneticFluxDensityUnit
- magneticFluxQuantum
- magneticFluxUnit
- magneticForce
- magneticMoment
- magneticMomentAnomaly
- magneticMonopole
- magneticMonopoleProblem
- magneticPole
- magneticPressure
- magneticProperty
- magneticStar
- magneticStorm
- magneticUnit
- magneticVariableStar
- magnetograph
- magnetoheliograph
- magnetohydrodynamics
- magnetoHydroDynamics
- magnetoOpticalEffect
- magnetoOpticalEffect
- magnetosphere
- magnetosphericSubstorm
- magnitude
- mainSequence
- mainSequenceStar
- majorAxis
- MaksutovTelescope
- manganese
- manganeseStar
- mantle
- manyworldsInterpretation
- map
- mapping
- maria
- MarkarianGalaxy
- mascon
- maser
- mass
- massDensity
- massDensityUnit
- massDistribution
- massExchange
- massFlow
- massFractionUnit
- massFunction
- massiveGalaxy
- massiveObject
- massiveStar
- massLoss
- massLuminosityRelation
- massRadiusRelation
- massRatio
- massToLightRatio
- massTransfer
- massUnit
- math
- mathConstant
- mathematicalAnalysis
- mathematicalConcept
- mathematicalConstant
- mathematicalModel
- mathematician
- mathematics
- mathEntity
- mathOperation
- matter
- matterObject
- MaunderMinimum
- maximum
- maximumEntropyMethod
- MaxwellDistribution
- MDivision
- MDwarf
- mean
- meanAnomaly
- meanElement
- meanEquinox
- meanFreePath
- meanIntensity
- meanSolarTime
- measurement
- measuringInstrument
- mechanicalComponent
- mechanicalProperty
- mechanics
- mechanics
- median
- mediumBandPhotometry
- megalithicAstronomy
- megamaser
- MeinelBand
- meitnerium
- memoryLocation
- mendelevium
- mercury
- mercuryManganeseStar
- merger
- mergingGalaxies
- meridian
- meridian
- meridianCircle
- meridianObservation
- meson
- mesopause
- mesosphere
- MeStar
- mestelDisk
- metagalaxy
- metalAbsorptionLineSystem
- metalAbundance
- metalDeficientStar
- metalLine
- metalPoorStar
- metalRichStar
- meteor
- meteorCamera
- meteorite
- meteoriteCrater
- meteoriteImpact
- meteoroid
- meteoroidDustCloud
- meteorology
- meteorShower
- meteorStream
- meteorTrail
- methane
- metonicCycle
- metricUnit
- metrology
- MeVariableStar
- MGiant
- MichelsonInterferometer
- MichelsonInterferometry
- MichieModel
- microchannelPlate
- microdensitometer
- microdensitometry
- micrometeorite
- micrometeoroid
- micrometer
- microphotometer
- microprocessor
- microturbulence
- microwave
- microwaveAntenna
- microwaveBackground
- microwaveEmission
- microwaveImaging
- microwaveRadiation
- microwaveSpectroscopy
- microwaveSpectrum
- MieScattering
- millimeterAstronomy
- millimeterRadiation
- millisecondPulsar
- MillsCrossAntenna
- MilneEddingtonApproximation
- mineralDeposit
- mineralogy
- minimum
- minorAxis
- minorPlanetFamily
- MiraStar
- MiraVariableStar
- mirror
- mirrorCell
- missingMass
- missingMassProblem
- MjdTime
- MkClassification
- MksUnit
- mksUnit
- MLogarithm
- MMagnitude
- MMultiplication
- MNaturalLogarithm
- mode
- model
- model
- modification
- ModifiedNewtonianDynamics
- modulation
- modulationTransferFunction
- molality
- molarity
- molarVolumeOfIdealGas
- moldavite
- molecularAstrophysics
- molecularBand
- molecularCloud
- molecularElectronicState
- molecularHydrogen
- molecularLine
- molecularSpectroscopy
- molecularSpectrum
- molecule
- molybdenum
- momentum
- MOND
- monochromator
- MonteCarloTechnique
- Moonquake
- morphology
- motion
- mottle
- movingClusterParallax
- mRegion
- MStar
- MSubdwarf
- MSubgiant
- MSubtract
- MSubtraction
- MSupergiant
- MTheory
- MullikenBand
- multiChannelDetector
- multiChannelSpectrograph
- multiColorPhotometry
- multiFiberSpectrograph
- multiPeriodicPulsation
- multiPeriodicVariableStar
- multipleGalaxy
- multipleMirrorTelescope
- multipleStar
- multiplet
- multiplication
- Multiplication
- multipoleExpansion
- multiSlitSpectrograph
- multiviewProjection
- muon
- muonNeutrino
- nadir
- nadir
- nakedSingularity
- narrowBandPhotometry
- NasmythFocus
- naturalLineBroadening
- naturalLineWidth
- naturalLogarithm
- naturalSatellite
- nauticalAlmanac
- NavarroFrenkWhiteProfile
- NavierStokes
- nbody
- nBodyProblem
- nBodySimulation
- nearbyDwarf
- nearbyGalaxy
- nearbyStar
- nearEarthAsteroid
- nearInfraredRadiation
- nearUltravioletRadiation
- nebula
- nebularFilament
- nebularVariableStar
- negativeHIon
- neighborhood
- neodymium
- neon
- neptunium
- NeumannLine
- neutralDensityFilter
- neutralGas
- neutralGas
- neutrino
- neutron
- neutronStar
- NewtonianFocus
- NewtonianGravitation
- NewtonianGravity
- NewtonianTelescope
- NewtonsLawOfMotion
- NGalaxy
- nickel
- nightSkyBrightness
- nightVision
- niobium
- nitrogen
- NMagnitude
- nobelium
- noctilucentCloud
- node
- noise
- nomenclature
- nonacceleratingReferenceFrame
- nonDiscreteParticleCode
- nonEquilibriumFlow
- nonHomogeneousEquation
- nonInteger
- nonLteTransfer
- nonMainSequenceStar
- nonRadialPulsation
- nonrotatingReferenceFrame
- nonThermalParticle
- nonThermalRadiation
- nonThermalSource
- northernHemisphere
- northPoint
- note
- nova
- novaLikeVariable
- novaStar
- NStar
- nuclearAstrophysics
- nuclearDensity
- nuclearFission
- nuclearFusion
- nuclearMagneton
- nuclearPhysics
- nuclearRadiation
- nuclearReaction
- nuclearScienceUnit
- nucleosynthesis
- nucleusCelestialObject
- number
- number
- numberDensityPerUnitMass
- numeric
- numericalAnalysis
- numericalIntegration
- numericalMethod
- numericalSimulation
- numericSetting
- nutation
- OAssociation
- ObAssociation
- objective
- objectiveGrating
- objectivePrism
- oblateness
- oblateSpheroid
- obliqueProjection
- obliqueRotator
- obliquityOfEcliptic
- observation
- observation
- observationalCosmology
- observatory
- observingTechnique
- ObStar
- ObSupergiant
- obtuseAnge
- OccamsRazor
- occultation
- occultingDisk
- oceanography
- oceanTide
- octagon
- octahedron
- ODwarf
- OefStar
- OeStar
- OfStar
- OGiant
- OhAbsorption
- OhCloud
- OhEmission
- OhIrStar
- OhLine
- OhMaser
- OhSource
- OIiiLine
- OIiLine
- OILine
- OIvLine
- OlbersParadox
- oldStar
- OMagnitude
- OmegaBaryon
- OmegaLambda
- OmegaMass
- OmegaMatter
- OmegaNaught
- omegaNeutrino
- OmegaParameter
- one-D_Shape
- onLineSystem
- OortCloud
- OortFormulae
- OosterhoffGroup
- opacity
- openCluster
- openClusterCatalog
- openStarCluster
- openString
- openUniverse
- operatingSystem
- operation
- operationOnMeasurement
- opposition
- optical
- opticalAberration
- opticalBurst
- opticalComponent
- opticalDepth
- opticalDesign
- opticalDoubleStar
- opticalFiber
- opticalFilm
- opticalFilter
- opticalFlare
- opticalGlass
- opticalIdentification
- opticalInstrument
- opticalInterferometer
- opticalInterferometry
- opticalLaw
- opticallyViolentlyVariableObject
- opticalMaterial
- opticalObservation
- opticalObservatory
- opticalOutburst
- opticalPathlength
- opticalPosition
- opticalProperty
- opticalPulsar
- opticalRadar
- opticalScanners
- opticalSpectrograph
- opticalSpectroscopy
- opticalSurface
- opticalSystem
- opticalTelescope
- opticalTesting
- opticalTransferFunction
- opticalTransmissionWindow
- opticalWaveguide
- opticalWindow
- optics
- optics
- orbit
- orbitalAnomaly
- orbitalDynamics
- orbitalElement
- orbitalElement
- orbitalEvolution
- orbitalHump
- orbitalMotion
- orbitalPeriod
- orbitalTheory
- orbitalVelocity
- orbitDetermination
- OrderedCollection
- ordinaryDifferentialEquation
- organicMatter
- organicMolecule
- organization
- orientation
- origin
- origin
- originOfLongitude
- orrery
- orthographicProjection
- orthohydrogen
- orthoscopicEyepiece
- oscillatingUniverse
- oscillation
- oscillatorStrength
- osculatingOrbit
- osculatoryElement
- OsipkovMerrittModel
- osmium
- OStar
- OSubdwarf
- OSupergiant
- outburst
- outdatedBelief
- outerPlanet
- outgassing
- overabundance
- overtoneFrequency
- overtoneMode
- OViLine
- OVLine
- oxygen
- OxygenBBand
- oxygenBurning
- ozoneLayer
- PaAlpha
- pairAnnihilation
- pairingEnergy
- pairProduction
- paleomagnetism
- palladium
- parabaloid
- parabola
- parabolicAntenna
- parabolicMirror
- parabolicOrbit
- parabolicReflector
- parabolicVelocity
- paradox
- parahydrogen
- parallax
- parallelComputer
- parallelogram
- parallelProjection
- parameter
- parametricAmplifier
- parity
- parsec
- partialDifferentialEquation
- partialEclipse
- particle
- particleAcceleration
- particleAccretion
- particleBeam
- particleCreation
- particleDensity
- particleDensityUnit
- particleEscape
- particleInteraction
- particleMass
- particleMeshNbody
- particleProduction
- particlePropagation
- particleSpin
- particleSystem
- PaschenBackEffect
- PaschenLine
- PaschenSeries
- pastLightCone
- pBranch
- PBranch
- PCygniLineProfile
- peculiarGalaxy
- peculiarGiant
- peculiarMotion
- peculiarObject
- peculiarStar
- peculiarVariableStar
- peculiarVelocity
- pencilBeam
- pendulum
- PenroseProcess
- pentagon
- penumbra
- penumbralFilament
- periapsis
- periastron
- perigee
- perihelion
- perimeter
- period
- periodAgeRelation
- periodChange
- periodColorRelation
- periodDensityRelation
- periodDetermination
- periodicComet
- periodicOrbit
- periodicVariableStar
- periodLuminosityColorRelation
- periodLuminosityRelation
- periodMassRelation
- periodOfRepetion
- periodRadiusRelation
- periodSpectrumRelation
- peripheral
- person
- perspectiveProjection
- perturbation
- perturbationAnalysis
- perturbationTheory
- petrology
- PfundSeries
- Pg1159Star
- phaseAngle
- phaseAngle
- phasedArray
- phaseDefect
- phaseDifference
- phaseEffect
- phaseError
- phaseFunction
- phaseRotator
- phaseSensitiveDetector
- phaseShift
- phaseSpace
- phaseSwitching
- phaseSwitchingInterferometer
- phaseWave
- PhillipsBand
- phosphorescence
- phosphorescentScintillation
- phosphorus
- photocathode
- photochemistry
- photoconductiveCell
- photodiode
- photodissociation
- photoelectricInstrument
- photoelectricMagnitude
- photoelectricPhotometer
- photoelectricPhotometry
- photoelectronicDevice
- photogrammetry
- photograph
- photographicAstrometry
- photographicDeveloper
- photographicEmulsion
- photographicFilm
- photographicFilter
- photographicInstrument
- photographicMagnitude
- photographicMaterial
- photographicPhotometry
- photographicPlate
- photographicProcessing
- photography
- photoheliograph
- photoionization
- photoluminescence
- photoluminescence
- photometer
- photometricElement
- photometricParallax
- photometricPeriod
- photometricStandardStar
- photometricSystem
- photometry
- photometryUnit
- photomultiplierTube
- photon
- photonCountingSystem
- photonics
- photosphere
- photovisualMagnitude
- photovoltaicCell
- physicalConstant
- physicalDistance
- physicalLaw
- physicalObject
- physicalObjectMeasurement
- physicalProcess
- physicalRelation
- physicalTheory
- physicalTheoryEntity
- physicist
- physicoChemicalConstant
- physics
- physics
- physicsTheory
- PiAlpha
- PiBeta
- PickeringLine
- picketFenceModel
- pion
- pitchAngle
- pixel
- plage
- planarProjection
- PlanckBlackBodyFormula
- PlanckConstant
- PlanckEnergy
- PlanckLength
- PlanckMass
- PlanckTime
- plane
- planePolarization
- planet
- planetar
- planetarium
- planetary
- planetaryAlignment
- planetaryNebula
- planetaryNebulaCatalog
- planetaryRing
- planetarySystem
- planetarySystemPart
- planetaryTheory
- planetEquator
- planetesimal
- planetocentricCoordinate
- planetographicCoordinate
- planetology
- planetSatellite
- plasma
- plasmaCloud
- plasmaJet
- plasmaLoop
- plasmapause
- plasmaPhysics
- plasmaWave
- platinum
- PlummerModel
- plutonium
- PMagnitude
- PogsonScale
- PoincareTheorem
- point
- pointingAccuracy
- pointingError
- pointSpreadFunction
- Poisson
- polarAngle
- polarAxis
- polarAxis
- polarCap
- polarCoordinateSystem
- polarDiagram
- polarimeter
- polarimetry
- polarizationChargeSeparation
- polarizedLight
- polarMotion
- polarOrbit
- polarRadialCoordinate
- polarRegion
- polarTide
- pole
- polishing
- pollution
- polonium
- polycyclicHydrocarbon
- polygon
- polyhedron
- polynomial
- polytrope
- polytrope
- populationIiCepheid
- populationIiiStar
- populationIiStar
- populationInversion
- populationIStar
- position
- positionAngle
- positionSensitiveProportionalCounter
- positron
- postAsymptoticGiantBranch
- postMainSequenceStar
- potassium
- potential
- potentialEnergy
- potentialGradient
- potentialTheory
- power
- powerLawFit
- powerOf
- powerUnit
- PoyntingRobertsonEffect
- pProcess
- praseodymium
- preamplifier
- precession
- precision
- precursorPulse
- prediction
- prefix
- preGalacticStar
- preMainSequenceStar
- preNova
- preSolarNebula
- pressure
- pressureBroadening
- pressureGradient
- pressureUnit
- preSupernova
- primaryLens
- primaryMirror
- primaryStar
- primeFocus
- primordialFireball
- primordialGalaxy
- principalInvestigator
- principle
- prism
- prism
- prismSpectrograph
- probability
- probabilityDistribution
- probabilityOf
- probabilityofExceedingValue
- probabilityOfSpontaneousEmission
- problem
- profile
- progenitor
- program
- project
- projection
- projectionOnto3D_Shape
- prolateSpheroid
- promethium
- prominence
- prominenceEruption
- propagation
- properMotion
- property
- proportionalCounter
- protactinium
- protocluster
- protogalaxy
- proton
- protonDecay
- protonProtonReaction
- protoplanet
- protoplanetaryNebula
- protoStar
- protostar
- protostellarDisk
- publication
- pulsar
- pulsatingVariableStar
- pulsation
- pulsationMode
- pulsationTheory
- pulse
- pulseCounter
- pulseCounting
- pulseDuration
- pulseEnergy
- pulseIntensity
- pulseProfile
- pulseStructure
- pulseWidth
- pulseWindow
- PurkinjeEffect
- purpose
- pyramid
- qBranch
- QBranch
- QMagnitude
- quadralateral
- quadrant
- quadrantDetector
- quadrature
- quanta
- quantity
- quantityEntity
- quantization
- quantumChromodynamics
- quantumCosmology
- quantumEfficiency
- quantumElectrodynamics
- quantumFieldTheory
- quantumGravity
- quantumLaw
- quantumMechanics
- quantumMechanicsInterpretation
- quantumOfCirculation
- quantumQuantity
- quantumTheory
- quark
- quarkColor
- quarterWavePlate
- quasar
- quasarGalaxyPair
- quiescentProminence
- quietSun
- radar
- radarAstronomy
- radarEquipment
- radarMapping
- radarTelescope
- radialCoordinate
- radialPulsation
- radialVelocity
- radiantMeteor
- radiantMovingCluster
- radiation
- radiationBelt
- radiationDamping
- radiationField
- radiationMeasurement
- radiationMechanism
- radiationPressure
- radiationScattering
- radiationTemperature
- radiativeBraking
- radiativeEquilibrium
- radiativeRecombination
- radiativeTransfer
- radical
- radioAbsorption
- radioactiveDecay
- radioactivity
- radioactivityUnit
- radioAntenna
- radioAstrometry
- radioAstronomy
- radioBackground
- radioBurst
- radioCore
- radioEmission
- radioFlare
- radioFrequency
- radioGalaxy
- radioheliograph
- radioInterference
- radioInterferometer
- radioInterferometry
- radioJet
- radiometer
- radiometry
- radioObservatory
- radioOccultation
- radioPulsar
- radioQuietQuasar
- radioRadiation
- radioRecombinationLine
- radioSource
- radioSourceCatalog
- radioSourceCount
- radioSpectrograph
- radioSpectroscopy
- radioSpectrum
- radioStar
- radioStructure
- radioTelescope
- radioTransmissionWindow
- radioWaveguide
- radium
- radius
- radiusLuminosityRelation
- radon
- raidArray
- RamanEffect
- RamanScattering
- RamanSpectroscopy
- RamanSpectrum
- ramPressure
- RamsdenEyepiece
- rangeFinder
- RankineHugoniotRelation
- rapidBurst
- rapidOscillation
- rareEarth
- RAssociation
- ratio
- ratio
- ray
- ray
- Rayleigh
- RayleighCriterion
- RayleighLimit
- RayleighNumber
- RayleighScattering
- RayleighTaylorInstability
- RazinEffect
- RBand
- RBranch
- RCanisMajorisStar
- RCoronaeBorealisStar
- readOutNoise
- realAnomaly
- reasoningProcess
- receiver
- recombination
- recombinationLine
- recombinationLine
- rectangle
- rectangularPrism
- recurrentNova
- reddenedStar
- reddening
- reddeningLaw
- redDwarf
- redDwarfFlareStar
- redGiant
- redGiantBump
- redGiantClump
- redGiantTip
- redshift
- redshiftDistanceRelation
- redshiftMagnitudeRelation
- redStar
- redSupergiant
- reductionMethod
- reference
- referenceFrame
- reflectingTelescope
- reflection
- reflectionGrating
- reflectionNebula
- reflectorAntenna
- refractingTelescope
- refraction
- refractionAngle
- refractiveIndex
- region
- regionOfSky
- regressionOfNode
- regressionRelation
- relationship
- relativisticAstrophysics
- relativisticCosmology
- relativisticDisk
- relativisticEffect
- relativisticElectroDynamics
- relativisticElectron
- relativisticFluidDynamics
- relativisticMechanics
- relativisticParticle
- relativisticPlasma
- relativisticStar
- relativisticVelocity
- relativity
- relaxationTime
- remoteControlSystem
- remoteSensing
- research
- reseaux
- residualIntensity
- resistance
- resistanceUnit
- resolution
- resonanceGap
- resonanceLine
- restMassEnergy
- retardation
- reticle
- reticonArray
- reverseVector
- rgbPhotometry
- RgbTipDistance
- rguPhotometry
- rhenium
- rhoCassiopeiaeStar
- rhodium
- rhombus
- RiemannEllipsoid
- rightAngle
- rightAscension
- rightTriangle
- rigidBodyRotation
- rill
- ring
- ringDivision
- ringGalaxy
- ringNebula
- riseTime
- RitcheyChretienTelescope
- RMagnitude
- RocheLimit
- RocheLobe
- rocketBorneInstrument
- roentgenium
- rootMeanSquare
- RosselandOpacity
- rotatingBody
- rotatingCoordinate
- rotatingReferenceFrame
- rotatingShell
- rotatingStar
- rotation
- rotation
- rotationalVelocity
- rProcess
- RrabStar
- RraStar
- RrbStar
- RrcStar
- RrLyraeStar
- RrTelescopiiStar
- RsCanumVenaticorumStar
- RStar
- rubidium
- runawayStar
- ruthenium
- rutherfordium
- RvTauriStar
- RwAurigaeStar
- RydbergConstant
- SahaEquation
- SalpeterFunction
- samarium
- sampling
- SarosCycle
- satellite
- satellite
- satelliteBorneInstrument
- satelliteLaserRanging
- SbfDistance
- scaleHeight
- scandium
- scattering
- SchmidtCamera
- SchmidtTelescope
- SchonbergChandrasekharLimit
- SchwarzschildMetric
- SchwarzschildRadius
- science
- scienceInstitution
- scientificField
- scientificField
- scientist
- scintillation
- scintillationCounter
- SDoradusStar
- seaborgium
- searchForExtraterrestrialLife
- season
- seasonalPhenomena
- secondaryCosmicRay
- secondaryMirror
- secondaryStar
- secondOrderPerturbationAnalysis
- secularParallax
- seeing
- seeingMonitor
- segmentedOptics
- segmentedPowerLawFit
- seismology
- selectionEffect
- selectiveAbsorption
- selenium
- selenocentricCoordinate
- selenology
- selfAbsorption
- selfCalibrationMethod
- semiBariumStar
- semiconductorDevice
- semiDetachedBinaryStar
- semiForbiddenLine
- semimajorAxis
- semimajorAxis
- semimajorRadius
- semiminorAxis
- semiminorAxis
- semiminorRadius
- semiRegularVariableStar
- sensitivity
- sensitometer
- separation
- set
- setOfLines
- setOfMolecularLines
- setting
- setting
- sextant
- Seyfert1
- Seyfert2
- SeyfertGalaxy
- SeyfertNucleus
- SGalaxy
- SGB
- SGL
- SGX
- SGY
- SGZ
- shadowBand
- shape
- shapedReflector
- shell
- shellBurning
- shellEjection
- shellStar
- shepherdSatellite
- shock
- shockWave
- shortPeriodVariableStar
- shotNoise
- shutter
- side
- sidelobe
- siderealTime
- siderealYear
- siderostat
- sigma8
- signalAnalysis
- signalDetection
- signalProcessing
- signalToNoiseRatio
- silicon
- siliconBurning
- siliconMonoxide
- siliconStar
- silver
- silverCoating
- simulation
- simulation
- singularIsothermalSphere
- singularity
- SiOMaser
- siteProtection
- siteTesting
- SiUnit
- size
- sky
- skyBrightness
- skyNoise
- skySurvey
- slitMask
- SloanPhotometry
- slope
- slowNova
- smoothParticleHydrodynamics
- sodium
- softGammaRayRepeater
- solar
- solarActivity
- solarAstronomy
- solarAtmosphere
- solarConstant
- solarCorona
- solarCycle
- solarDay
- solarEclipse
- solarFilament
- solarInterior
- solarMotion
- solarNebula
- solarNeutrinoProblem
- solarObservatory
- solarOpticalTelescope
- solarOscillation
- solarParallax
- solarphysics
- solarPlanetaryRelation
- solarRadioTelescope
- solarStorm
- solarSurface
- solarSystemPlanet
- solarTelescope
- solarTerrestrialRelation
- solarWind
- solid
- solidAngle
- solidAngleUnit
- solstice
- soundSpeed
- source
- southernHemisphere
- southPole
- space
- space
- spaceAstrometry
- spaceAstronomy
- spaceBiology
- spaceDebris
- spaceExploration
- spaceGeodesy
- spaceLaw
- spaceMotion
- spaceMotion
- spaceObservatory
- spacePollution
- spaceProbe
- spaceProbeInstrument
- spaceResearch
- spaceScienceInstitution
- spaceTelescope
- spaceTimeCurvature
- spaceTimeSingularity
- spaceVehicle
- spaceVehicle
- specialNumber
- specialTheoryOfRelativity
- specificIntensity
- speckle
- speckleInterferometry
- spectralBand
- spectralBand
- spectralClassification
- spectralFeature
- spectralIndex
- spectralLine
- spectralResolution
- spectralType
- spectrograph
- spectrographSlit
- spectrography
- spectroheliograph
- spectrophotometer
- spectrophotometry
- spectroscopicAnalysis
- spectroscopicBinaryStar
- spectroscopy
- spectroscopy
- spectroscopy
- spectrum
- spectrumVariableStar
- speedOfLightInVacuum
- sphere
- sphericalAberration
- sphericalCoordinate
- sphericalCoordinateSystem
- sphericalHarmonicExpansion
- sphericalRadialCoordinate
- sphericalSystem
- spheroid
- SphNbody
- SphSimulation
- spicule
- spiralArm
- spiralDensityWave
- spiralGalaxy
- spiralGalaxyMeasurement
- sProcess
- square
- SStar
- stability
- stableLagrangianPoint
- StackelPotential
- standardCandle
- standardDeviation
- standardEpoch
- standardStar
- star
- starAssociation
- starAtlas
- starburstGalaxy
- starCatalog
- starCluster
- starCount
- starDistribution
- starFormation
- StarkBroadening
- starMeasurement
- starPart
- starSimulation
- starspot
- starSystemCatalog
- stateOfMatter
- statics
- staticUniverse
- statisticalDistribution
- statisticalParallax
- statisticalRelation
- statistics
- statisticsEntity
- steadyStateTheory
- StefanBoltzmannConstant
- stellar
- stellarAssociation
- stellarAstronomy
- stellarAtmosphere
- stellarBlackHole
- stellarDynamics
- stellarEvolution
- stellarEvolution
- stellarEvolutionPhase
- stellarInterior
- stellarLayer
- stellarMotion
- stellarObject
- stellarOscillation
- stellarPopulation
- stellarRemnant
- stellarRing
- stellarStructure
- stellarSurfaceFeature
- stellarSystemCatalog
- stellarTheory
- stellarWind
- stickyParticleNbody
- stimulatedEmission
- stimulatedRadiation
- stokesParameter
- strangeQuark
- stratopause
- stratosphere
- streakPhotography
- streamer
- stressUnit
- string
- stringFormat
- stringTheory
- stroboscope
- StromgrenPhotometry
- StromgrenSphere
- strongForceSymmetry
- strongInteraction
- strontium
- strontiumStar
- structure
- subatomicParticle
- subdwarf
- subgiant
- subluminousStar
- submillimeterAstronomy
- submillimeterRadiation
- subreflector
- subtraction
- sulfur
- summerSolstice
- sunlight
- sunspot
- sunspotCycle
- sunspotGroup
- sunspotNumber
- SunyaevZeldovichEffect
- supercluster
- superconductingTunnelJunction
- supergalacticCoordinates
- supergalacticCoordinateSystem
- supergalacticLatitude
- supergalacticLongitude
- supergalacticXcoordinate
- supergalacticXYZ
- supergalacticYcoordinate
- supergalacticZcoordinate
- supergiant
- supergranulation
- supergravity
- superhump
- superMassiveBlackHole
- supermassiveStar
- supermultiplet
- supernova
- supernovaEnvelope
- supernovaExplosion
- supernovaRemnant
- superstringTheory
- supersymmetricQuantumFieldTheory
- supersymmetricStandardModel
- supersymmetry
- supportSystem
- surfaceArea
- surfaceArea
- surfaceBrightness
- surfaceGravity
- surfaceMassDensityUnit
- surfaceOfCelestialBody
- surfacePhotometry
- surfaceProperty
- survey
- SuUrsaeMajorisStar
- SVulpeculaeStar
- SwanBand
- SwanBand
- SxArietisStar
- SxPhoenicisStar
- symbioticNova
- symbioticStar
- symbol
- symmetry
- symmetryBreaking
- synchronousDetector
- synchronousRotation
- synchrotronRadiation
- synchrotronRadiation
- synodicPeriod
- system
- system
- systemMeasurement
- systemOfGalaxies
- systemOfStars
- syzygy
- tail
- tangentialVelocity
- tangentialVelocity
- tantalum
- tArray
- TAssociation
- tau
- tauNeutrino
- taxonomy
- TDwarf
- teachingInAstronomy
- technetium
- technetiumLine
- technetiumStar
- tektite
- telescope
- telescopeArray
- telescopeConstruction
- telescopeDesign
- telescopeInstrument
- telescopeMirror
- telescopeMounting
- television
- televisionCamera
- televisionDetector
- telluricLine
- tellurium
- temperature
- temperatureControl
- temperatureEffect
- temperatureFluctuation
- temperatureScale
- temperatureUnit
- temperatureZone
- terbium
- terminatorLine
- terrestrialLatitude
- terrestrialLongitude
- terrestrialRadiation
- tertiaryMirror
- tertiaryStar
- testing
- thallium
- theoreticalAstrophysics
- theory
- theoryRelatedConcept
- thermalConductivity
- thermalConductivityUnit
- thermalEmission
- thermalEnergy
- thermalEquilibrium
- thermalHistory
- thermalInstability
- thermalProperty
- thermalRadiation
- thermalStability
- thermalStructure
- thermionicEmission
- thermodynamicEquilibrium
- thermodynamics
- thermodynamicsLaw
- thermoluminescence
- thermonuclearReaction
- thermosphere
- thickness
- thinFilm
- ThomsonCrossSection
- ThomsonScattering
- thorium
- thoughtExperiment
- three-D_Shape
- threeBodyCode
- threeBodyProblem
- threeDimensionalSpectroscopy
- threeDimensionalSpectrum
- thresholdEnergy
- thulium
- tidalDisruption
- tidalDistortion
- tidalFriction
- tidalInteraction
- tidalRadius
- tide
- time
- time
- timeMeasurement
- timeResolvedSpectroscopy
- timeSignal
- timeStandard
- timeStep
- timeSynchronization
- timeUnit
- timingEquipment
- tin
- tipTiltMirror
- titanium
- titaniumOxide
- topdownScenario
- topocentricCoordinate
- topography
- topQuark
- torus
- torus
- totalEclipse
- traceElement
- tracking
- trajectory
- transferFunction
- transformation
- transformation
- transit
- transitCircle
- transitInstrument
- transitionProbability
- transitionRegion
- transitTelescope
- transitTime
- translation
- transmission
- transmissionGrating
- transNeptunianObject
- transparency
- transplutonianPlanet
- transportProcess
- transverseVelocity
- trapezoid
- treeCodeCalculation
- triangle
- triaxialSystem
- trigonometricParallax
- trigonometry
- tripleStar
- tripleStellarSystem
- tritium
- trojanGroup
- tropicalYear
- TropicOfCancer
- TropicOfCapricorn
- tropopause
- troposphere
- trueAnomaly
- truePosition
- TStar
- TSubdwarf
- TTauriStar
- TullyFisherRelation
- tungsten
- tupleDeclaration
- turbidity
- turbulence
- turbulence
- turbulenceEarthAtmosphere
- turbulenceStarAtmosphere
- turnoffPoint
- twilight
- twistorTheory
- two-D_Shape
- twoBodyCode
- twoBodyProblem
- twoColorDiagram
- twoColorPhotometry
- twoDimensionalDetector
- twoDimensionalSpectroscopy
- twoDimensionalSpectrum
- twoSpectrumBinaryStar
- typeIaSupernova
- typeIbSupernova
- typeIcSupernova
- typeIiSupernova
- UBand
- UGeminorumStar
- ultraLuminousGalaxy
- ultraviolet
- ultravioletAstronomy
- ultravioletBackground
- ultravioletCamera
- ultravioletColor
- ultravioletContinuum
- ultravioletDetector
- ultravioletExcessStar
- ultravioletExtinction
- ultravioletFilter
- ultravioletLine
- ultravioletLuminosity
- ultravioletObservatory
- ultravioletPhotography
- ultravioletPhotometry
- ultravioletRadiation
- ultravioletSource
- ultravioletSpectrograph
- ultravioletSurvey
- ultravioletTelescope
- UMagnitude
- umbra
- unaryOperation
- uncertainty
- uncertaintyPrinciple
- underabundance
- unifiedTheory
- union
- unit
- unit
- unitless
- unitVector
- UniversalTime
- universe
- universeSimulation
- unsharpMasking
- unstableLagrangianPoint
- upperAtmosphere
- upQuark
- upsilonSagittariiStar
- uranium
- urcaProcess
- Url
- Ut1
- UuHerculisStar
- UvCetiStar
- UvPerseiStar
- UxUrsaeMajorisStar
- vacuum
- vacuumTechnique
- valueList
- values
- vanadium
- vanAllenRadiationBelt
- VanDerWaals
- vanDerWaalsForce
- vaporDeposition
- variability
- variableEruption
- variableSource
- variableStar
- variance
- VBand
- vector
- vectorAddition
- vectorCrossProduct
- vectorDeclaration
- vectorDotProduct
- vectorOperation
- vectorSubtraction
- velocity
- velocityCurve
- velocityDispersion
- velocityDistribution
- velocityEllipsoid
- velocityField
- velocityOfLight
- velocitySpace
- velocityUnit
- ventilation
- vernalEquinox
- vertex
- vertexOfParabola
- verticalCircle
- VeryLargeArray
- veryLargeTelescope
- veryLongBaselineInterferometer
- veryLongBaselineInterferometry
- vibration
- vibrationalEnergy
- vibrationalSpectrum
- vignetting
- VilniusPhotometry
- virialAnalysis
- virialTheorem
- virtualObservatory
- viscosity
- viscosityUnit
- visibilityFunction
- visibleRadiation
- visibleSpectrum
- vision
- visualAcuity
- visualBinaryStar
- visualMagnitude
- visualObservation
- VlasovEquation
- VMagnitude
- void
- VoigtProfile
- volatile
- volcano
- volume
- volume
- volumeUnit
- vonZeipelTheorem
- VphGrating
- VySculpturisStar
- W20
- WalravenPhotometry
- water
- waterIce
- waterLiquid
- waterMaser
- waterVapor
- wave
- waveformAnalysis
- waveguide
- wavelength
- waveMeasurement
- waveMotion
- waveNumberUnit
- wavePropagation
- WcnStar
- WcStar
- weakGaugeBoson
- weakGaugeSymmetry
- weakGBandStar
- weakInteraction
- weakLineTTauriStar
- weakMixingAngle
- weatherStation
- webcam
- webPage
- WernerLine
- whiteDwarf
- whiteHole
- wideAngleLens
- wideBinaryStar
- wideFieldTelescope
- width
- width
- WilsonBappuEffect
- WilsonEffect
- window
- windVane
- winterSolstice
- Wminus
- WnStar
- WolfDiagram
- WolfRayetStar
- workFunction
- workUnit
- Wplus
- WUrsaeMajorisStar
- WVirginisStar
- WVirTypeStar
- WzSagittaeStar
- x
- xCoordinate
- xenon
- XRayAbsorption
- XRayAstronomy
- XRayBackground
- XRayBinaryStar
- XRayBrightPoint
- XRayBurst
- XRayContinuum
- XRayDetector
- XRayDiffraction
- XRayEmission
- XRayFlare
- XRayFluorescence
- XRayIdentification
- XRayLine
- XRayLuminosity
- XRayMap
- XRayNova
- XRayObservatory
- XRayPolarization
- XRayPulsar
- XRayQuasar
- XRayRadiation
- XRayScattering
- XRaySource
- XRaySpectrograph
- XRaySpectroscopy
- XRaySpectrum
- XRayStar
- XRayStructure
- XRaySurvey
- XRayTelescope
- XRayTransient
- y
- YagiAntenna
- yArray
- yCoordinate
- year
- YerkesClass
- YerkesClassification
- yokeMounting
- youngDiskCepheid
- youngStar
- youngStarCluster
- youngStellarObject
- ytterbium
- yttrium
- z
- ZAndromedaeStar
- ZCamelopardalisStar
- zCoordinate
- ZeemanSplitting
- zenith
- zenithAngle
- zenithDistance
- zenithHourlyRate
- zenithTelescope
- zenithTube
- zeroAgeHorizontalBranch
- zeroAgeMainSequence
- zeroPoint
- zeroPointEnergy
- zeroPointPressure
- zinc
- zirconium
- zirconiumStar
- Znaught
- zodiac
- zodiacalDust
- zodiacalDustCloud
- zodiacalLight
- zoneOfTotality
- ZzCetiStar