Stars from a variety of wellknown catalogs.

Entity["Star",name] or

represents an entity of type "Star".


gives the value of a specified property.


gives the value of a list of properties.


gives the value of a specified property modified by qualifier rules quali->vali.


gives the value of a property associated with a particular date specification.


represents a class of entities with values of propi defined by speci.

Sample Entities

Sample Entity Classes


  • AbsoluteMagnitudeabsolute magnitude
    AbsoluteMagnitudeBolometricabsolute bolometric magnitude
    AlphanumericNamealphanumeric name
    AlternateNamesalternate names
    AltitudeTransitnext transit altitude
    AngularDiameterFromEarthangular diameter
    AngularRadiusFromEarthangular radius
    Apoapsislargest distance from orbit center
    ApparentAltitudeapparent altitude
    ApparentMagnitudeapparent magnitude
    AzimuthRiseazimuth at rise
    AzimuthSetazimuth at set
    BayerNameBayer name
    BayerStandardNameBayer standard name
    BooleanRiseabove the horizon
    BVColorIndexBV color index
    DailyTimeAboveHorizondaily time above horizon
    Densitymean density
    Diameteraverage diameter
    DistanceFromEarthdistance from Earth
    DistanceFromSundistance from Sun
    DurchmusterungNameDurchmusterung name
    DurchmusterungStandardNameDurchmusterung standard name
    Eccentricityorbital eccentricity
    EffectiveTemperatureeffective temperature
    EntityClassesentity classes
    EntityTypeListentity type list
    EquatorialDiameterequatorial diameter
    EquatorialRadiusequatorial radius
    EscapeVelocityescape velocity
    FlamsteedNameFlamsteed name
    FlamsteedStandardNameFlamsteed standard name
    GalacticLatitudegalactic latitude
    GalacticLongitudegalactic longitude
    GeocentricEclipticLatitudegeocentric ecliptic latitude
    GeocentricEclipticLongitudegeocentric ecliptic longitude
    GlieseNameGliese catalog designation
    GlieseStandardNameGliese standard name
    Glyphastrological symbol
    GravitationalConstantMassProductgravitational constant mass product
    GreenwichHourAngleGreenwich hour angle
    HDNameHD catalog name
    HDNumberHD catalog number
    HeliocentricEclipticLatitudeheliocentric ecliptic latitude
    HeliocentricEclipticLongitudeheliocentric ecliptic longitude
    HelioCoordinatesheliocentric XYZ coordinates
    HipparcosNameHipparcos name
    HipparcosNumberHipparcos number
    HRNameHR catalog name
    HRNumberHR catalog number
    ICNumberIC number
    LifetimeEntropylifetime entropy
    LocalHourAnglelocal hour angle
    LuminosityMassRateEquivalentluminosity mass rate equivalent
    MainSequenceLifetimemain sequence lifetime
    MajorAxisorbital major axis
    MaximalAltitudeTimenext maximum altitude time
    MaximumAbsoluteMagnitudemaximum absolute magnitude
    MaximumApparentMagnitudemaximum apparent magnitude
    MinimumAbsoluteMagnitudeminimum absolute magnitude
    MinimumApparentMagnitudeminimum apparent magnitude
    MomentOfInertiarotational moment of inertia
    MultipleSystemMembermember of a multiple star system
    NGCNumberNGC number
    ObjectTypeobject type
    OrbitalAngularMomentumorbital angular momentum
    OrbitCenterorbit center
    OrbitPeriodorbital period
    Periapsissmallest distance from orbit center
    PolarDiameterpolar diameter
    PolarRadiuspolar radius
    PositionAngleposition angle
    ProperMotionproper motion
    ProperMotionDeclinationproper motion declination
    ProperMotionRightAscensionproper motion right ascension
    RadialVelocityradial velocity
    Radiusaverage radius
    RightAscensionright ascension
    RiseTimenext rise
    RotationalAngularMomentumrotational angular momentum
    RotationPeriodrotation period
    SAONameSAO catalog name
    SAONumberSAO catalog number
    Satellitesknown satellites
    SemimajorAxisorbital semimajor axis
    SetTimenext set
    SiderealHourAnglesidereal hour angle
    SpectralClassspectral class
    SpectralClassListspectral class list
    StarDistanceTimeSeriesdistance from Earth time series
    StarEndStatestellar end state
    StarTypestar type
    StationaryOrbitRadiusstationary orbit radius
    StationaryOrbitSpeedstationary orbit speed
    StellarEvolutionDiagramstellar evolution diagram
    SunElongationelongation from the Sun
    SurfaceAreasurface area
    SystemMemberssystem members
    TransitTimenext transit time
    TychoNumberTycho number
    VariablePeriodvariability period
    VariableStarNamevariable star name
    VariableStarTypevariable star type
    WDSIdentifierWDS identifier
    ZenithAnglezenith angle


  • "Star" entities include a large collection of stellar objects from a variety of catalogs, including subsets of the Yale Bright Star Catalog, the Hipparcos Catalogue, the Henry Draper Catalogue and the Gliese Catalogue.
  • "Star" entity classes include a large variety of groups based on aspects such as spectral types, chemical compositions, variable star types, constellation membership and catalog membership.
  • Some properties are available for the "Star" entity type as a whole and can be given using the form EntityValue["Star",property]. Such properties include:
  • "Properties"the list of available properties
    "PropertyCanonicalNames"the standard names of available properties
    "SampleEntities"a sample list of available entities (typically of length 10)
    "SampleEntityClasses"a sample list of available entity classes (typically of length 10)
    "EntityCount"number of entities available
    "Entities"the list of available entities
    "EntityCanonicalNames"the standard names of available entities
    "EntityClasses"the list of available entity classes
    "EntityClassCanonicalNames"the standard names of available entity classes
    "PropertyClasses"the list of available property classes
    "PropertyClassCanonicalNames"the standard names of available property classes
    "PropertyCount"number of properties available
  • The following annotations can be used in the third argument of EntityValue["Star",property,annotation]:
  • "Source"source information for the property
    "Date"the date associated with the entity-property value (if any)
    "EntityAssociation"an association of entities and entity-property values
    "PropertyAssociation"an association of properties and entity-property values
    "EntityPropertyAssociation"an association in which the specified entities are keys, and values are a nested association of properties and entity-property values
    "PropertyEntityAssociation"an association in which the specified properties are keys, and values are a nested association of entities and entity-property values
    "Dataset"a dataset in which the specified entities are keys, and values are an association of property names and entity-property values
  • The following annotations can be used in the second argument of EntityValue[property,annotation]:
  • "Qualifiers"the list of possible qualifiers for the property
    "QualifierValues"the list of possible values that can be given to each qualifier
    "DefaultQualifierValues"the list of default values for the property's qualifiers
    "Description"a brief textual description of the property
    "Definition"a detailed textual definition of the property
    "PhysicalQuantity"the physical quantity associated with the entity-property value
    "Unit"the unit associated with the entity-property value
  • A qualifier value of Automatic indicates that an applicable format of values can be used; e.g. for the "Date" qualifier, this includes a proper date or date span.


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Basic Examples  (8)

Use for discovery:

Find the effective temperature of a star:

Find the equatorial coordinates of a star:

Find the current sky position of a star from your location:

Get a list of classes of stars:

Find the spectral classes of barium stars:

Retrieve a dataset of all available properties for an entity:

Find the 5 brightest stars:

Scope  (16)

The 15 brightest stars as seen from Earth:

The constellations for the 10 brightest stars:

Distance from Earth to Sirius:

Distance in meters:

Position of Sirius:

Spectral class for the Sun:

Spectral class information in list form:

Alternate names for Sirius:

Henry Draper Memorial Catalogue number for Sirius:

Give the individual stars that form Alpha Centauri:

Give the name of Tau Ceti, including Greek letters:

Without special characters:

Ten brightest supergiants as seen from Earth:

The number of available supergiants:

The 10 brightest class-O stars:

The 10 brightest WolfRayet stars:

Implicit Entity Classes  (1)

The 10 nearest stars:

Distances in light years:

Spectral class information:

Property Classes  (1)

Represent equatorial coordinate properties associated with stars:

Get a list of available property classes for stars:

Find the list of properties included in a property class:

Obtain the property values for the properties in a property class for an entity:

Qualifiers  (2)

Some properties accept qualifiers:

The "Location" qualifier, which specifies the location of the observer, can accept an explicit GeoPosition, location-based Entity objects or queries that evaluate to one of these:

Dates  (1)

Date qualifiers can accept an explicit DateObject or queries that evaluate to a DateObject:

Date qualifiers can also be specified using Dated:

Applications  (10)

Plot the right ascension and declination of the 100 brightest stars, with tooltips for their names:

The corresponding picture for the 100 nearest stars:

Rank plot of absolute magnitudes of the 100 nearest stars:

Rank plot of absolute magnitudes of the 100 brightest stars:

Distribution of basic spectral classes for the 100 brightest stars:

Distribution for the 100 nearest stars:

Rank plot of the distances to the 100 nearest stars:

Differences between successive distances:

Get the correct color and simulate lighting for a star:

The colors of stars are an indication of their temperatures:

The habitable zone of an exoplanet is an ambiguous concept with no agreed-upon definition. There are several ways to go about determining what you might interpret as the habitable zone. All methods have a relation to their host star.

One way of determining the habitable zone is described in Whitmire, D. and Reynolds, R., "Circumstellar Habitable Zones: Astronomical Considerations," in Doyle, L. (ed.), Circumstellar Habitable Zones, Proceedings of the First International Conference, Travis House Publications, 1996: 117142. This method allows you to determine an inner and outer radius of the habitable zone around a star:

Relations to Other Entity Types  (1)

Stars are orbited by entities of type "Planet" or "Exoplanet":

Possible Issues  (1)

StarData combines star catalogs that select stars in different ways:

Neat Examples  (1)

Plot luminosity versus mass for nearby stars: