--- title: "AstronomicalRadioSource" language: "en" type: "Entity" summary: "Astronomical radio sources, primarily from the 3C catalog." canonical_url: "https://reference.wolfram.com/language/ref/entity/AstronomicalRadioSource.html" source: "Wolfram Language Documentation" related_guides: - title: "Entity Types" link: "https://reference.wolfram.com/language/guide/EntityTypes.en.md" --- # AstronomicalRadioSource Astronomical radio sources, primarily from the 3C catalog. [Related Interpreter](https://reference.wolfram.com/language/ref/interpreter/AstronomicalRadioSource.en.md) Entity["AstronomicalRadioSource", name] or Entity[...] represents an entity of type "AstronomicalRadioSource". Entity[...][prop] gives the value of a specified property. Entity[...][{prop1, …}] gives the value of a list of properties. Entity[...][prop, {quali -> vali, …}] gives the value of a specified property modified by qualifier rules quali -> vali. Entity[...][Dated[prop, date]] gives the value of a property associated with a particular date specification. EntityClass["AstronomicalRadioSource", {propi -> speci, …}] represents a class of entities with values of propi defined by speci. ## Sample Entities * Entity["AstronomicalRadioSource", "SagittariusAStar"]Entity["AstronomicalRadioSource", "3C273"]Entity["AstronomicalRadioSource", "3C234"]Entity["AstronomicalRadioSource", "3C89"]Entity["AstronomicalRadioSource", "3C400.1"]Entity["AstronomicalRadioSource", "3C153.1"]Entity["AstronomicalRadioSource", "3C76.1"]Entity["AstronomicalRadioSource", "3C66"]Entity["AstronomicalRadioSource", "3C171"]Entity["AstronomicalRadioSource", "3C424"]**…** ## Sample Entity Classes * EntityClass["AstronomicalRadioSource", "3CObject"]**…** ## Properties | | | | ------------------------------------------ | ------------------------------------- | | AlphanumericName | alphanumeric name | | AlternateNames | alternate names | | Altitude | altitude | | AltitudeMaximum | next maximum altitude | | AltitudeTransit | next transit altitude | | AngularDiameterFromEarth | angular diameter | | AngularRadiusFromEarth | angular radius | | ApparentAltitude | apparent altitude | | Azimuth | azimuth | | AzimuthRise | azimuth at rise | | AzimuthSet | azimuth at set | | BooleanRise | above the horizon | | Classes | classes | | Constellation | constellation | | DailyTimeAboveHorizon | daily time above horizon | | Declination | declination | | Diameter | average diameter | | DistanceFromEarth | distance from Earth | | DistanceFromSun | distance from Sun | | EntityClasses | entity classes | | EntityTypeList | entity type list | | EscapeVelocity | escape velocity | | FanaroffRileyClass | Fanaroff-Riley class | | GalacticLatitude | galactic latitude | | GalacticLongitude | galactic longitude | | GeocentricEclipticLatitude | geocentric ecliptic latitude | | GeocentricEclipticLongitude | geocentric ecliptic longitude | | Gravity | gravity | | GreenwichHourAngle | Greenwich hour angle | | HeliocentricEclipticLatitude | heliocentric ecliptic latitude | | HeliocentricEclipticLongitude | heliocentric ecliptic longitude | | HelioCoordinates | heliocentric ecliptic XYZ coordinates | | LocalHourAngle | local hour angle | | Mass | mass | | MaximalAltitudeTime | next maximum altitude time | | MeanFluxDensityAtOneHundredSeventyEightMHz | mean flux density at 178 MHz | | Name | name | | ObjectType | object type | | Radius | average radius | | Redshift | redshift | | RelatedObjects | related objects | | RightAscension | right ascension | | RiseTime | next rise | | SetTime | next set | | SiderealHourAngle | sidereal hour angle | | SpectralIndex | spectral index | | SunElongation | elongation from the Sun | | TransitTime | next transit time | | ZenithAngle | zenith angle | ## Details * ``"AstronomicalRadioSource"`` entities primarily include objects surveyed as part of the Third Cambridge Catalogue of Radio Sources. * Some properties are available for the ``"AstronomicalRadioSource"`` entity type as a whole and can be given using the form ``EntityValue["AstronomicalRadioSource", 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["AstronomicalRadioSource", 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. --- ## Examples (14) ### Basic Examples (6) Use ctrl+= for discovery: ```wl In[1]:= [image] Out[1]= Entity["AstronomicalRadioSource", "SagittariusAStar"] ``` --- Find the mean flux density at 178 MHz of an astronomical radio source: ```wl In[1]:= Entity["AstronomicalRadioSource", "3C273"]["MeanFluxDensityAtOneHundredSeventyEightMHz"] Out[1]= Quantity[67.`3., "Janskies"] ``` --- Retrieve a dataset of all available properties for an entity: ```wl In[1]:= Entity["AstronomicalRadioSource", "3C274"]["Dataset"] Out[1]= Dataset[Association[EntityProperty["AstronomicalObject", "Altitude"] -> Quantity[MixedMagnitude[{12, 28, 32.0420888250616767157`2.853358017724998}], MixedUnit[{"AngularDegrees", "Arcminutes", "Arcseconds"}]], EntityProperty["Astronomica ... nds"}]], EntityProperty["Thing", "EntityClasses"] -> {EntityClass["AstronomicalRadioSource", "3CObject"]}, EntityProperty["Thing", "EntityTypeList"] -> {EntityType["AstronomicalRadioSource"]}, EntityProperty["Thing", "Name"] -> "3C 274"]] ``` --- Represent all of the astronomical radio sources with the 5 largest values for mean flux density at 178 MHz: ```wl In[1]:= EntityClass["AstronomicalRadioSource", {"MeanFluxDensityAtOneHundredSeventyEightMHz" -> TakeLargest[5]}]//EntityList Out[1]= {Entity["AstronomicalRadioSource", "3C461"], Entity["AstronomicalRadioSource", "3C405"], Entity["AstronomicalRadioSource", "3C274"], Entity["AstronomicalRadioSource", "3C400"], Entity["AstronomicalRadioSource", "3C410.1"]} ``` --- Find the equatorial coordinates of a star: ```wl In[1]:= Entity["AstronomicalRadioSource", "SagittariusAStar"][{"RightAscension", "Declination"}] Out[1]= {Quantity[MixedMagnitude[{17, 45, 40.046}], MixedUnit[{"HoursOfRightAscension", "MinutesOfRightAscension", "SecondsOfRightAscension"}]], Quantity[MixedMagnitude[{-29, 0, -28.}], MixedUnit[{"AngularDegrees", "Arcminutes", "Arcseconds"}]]} ``` --- Find the current sky position of a star from your location: ```wl In[1]:= EntityValue[Entity["AstronomicalRadioSource", "SagittariusAStar"], {"Altitude", "Azimuth"}, "PropertyAssociation"] Out[1]= <|"Altitude" -> Quantity[MixedMagnitude[{-71, -57, -56.}], MixedUnit[{"AngularDegrees", "Arcminutes", "Arcseconds"}]], "Azimuth" -> Quantity[MixedMagnitude[{57, 21, 31.}], MixedUnit[{"AngularDegrees", "Arcminutes", "Arcseconds"}]]|> ``` ### Scope (8) #### Implicit Entity Classes (1) Represent all of the astronomical radio sources with the 5 largest values for mean flux density at 178 MHz: ```wl In[1]:= EntityClass["AstronomicalRadioSource", {"MeanFluxDensityAtOneHundredSeventyEightMHz" -> TakeLargest[5]}]; ``` Get a list of all the astronomical radio sources: ```wl In[2]:= EntityList[%] Out[2]= {Entity["AstronomicalRadioSource", "3C461"], Entity["AstronomicalRadioSource", "3C405"], Entity["AstronomicalRadioSource", "3C274"], Entity["AstronomicalRadioSource", "3C400"], Entity["AstronomicalRadioSource", "3C410.1"]} ``` #### Property Classes (4) Represent equatorial coordinate properties associated with astronomical radio sources: ```wl In[1]:= EntityPropertyClass["AstronomicalRadioSource", "EquatorialCoordinates"] Out[1]= EntityPropertyClass["AstronomicalRadioSource", "EquatorialCoordinates"] ``` --- Get a list of available property classes for astronomical radio sources: ```wl In[1]:= EntityValue["AstronomicalRadioSource", "PropertyClasses"] Out[1]= {EntityPropertyClass["AstronomicalRadioSource", "BasicProperties"], EntityPropertyClass["AstronomicalRadioSource", "EquatorialCoordinates"], EntityPropertyClass["AstronomicalRadioSource", "GalacticCoordinates"], EntityPropertyClass["AstronomicalRad ... icEclipticCoordinates"], EntityPropertyClass["AstronomicalRadioSource", "HeliocentricEclipticCoordinates"], EntityPropertyClass["AstronomicalRadioSource", "HorizonCoordinates"], EntityPropertyClass["AstronomicalRadioSource", "LocationProperties"]} ``` --- Find the list of properties included in a property class: ```wl In[1]:= EntityPropertyClass["AstronomicalRadioSource", "EquatorialCoordinates"]["Properties"] Out[1]= {EntityProperty["AstronomicalRadioSource", "RightAscension"], EntityProperty["AstronomicalRadioSource", "Declination"]} ``` --- Obtain the property values for the properties in a property class for an entity: ```wl In[1]:= EntityValue[Entity["AstronomicalRadioSource", "3C274"], EntityPropertyClass["AstronomicalRadioSource", "EquatorialCoordinates"]] Out[1]= {Quantity[MixedMagnitude[{12, 30, 50.0}], MixedUnit[{"HoursOfRightAscension", "MinutesOfRightAscension", "SecondsOfRightAscension"}]], Quantity[MixedMagnitude[{12, 23, 31.}], MixedUnit[{"AngularDegrees", "Arcminutes", "Arcseconds"}]]} ``` #### Qualifiers (3) Some properties accept qualifiers: ```wl In[1]:= EntityValue[EntityProperty["AstronomicalRadioSource", "Constellation"], "Qualifiers"] Out[1]= {"Date"} In[2]:= EntityValue[EntityProperty["AstronomicalRadioSource", "RiseTime"], "Qualifiers"] Out[2]= {"Date", "Location"} ``` --- 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: ```wl In[1]:= EntityValue[Entity["AstronomicalRadioSource", "3C274"], EntityProperty["AstronomicalRadioSource", "RiseTime", {"Location" -> #}]& /@ {GeoPosition[{40.1, -88.2}], \[FreeformPrompt]["Joplin"], \[FreeformPrompt]["capital city of Iowa"]}] Out[1]= {DateObject[{2025, 6, 26, 12, 18}, "Minute", "Gregorian", -5.], DateObject[{2025, 6, 26, 12, 47}, "Minute", "Gregorian", -5.], DateObject[{2025, 6, 26, 12, 37}, "Minute", "Gregorian", -5.]} ``` ##### Dates (1) Date qualifiers can accept an explicit ``DateObject`` or queries that evaluate to a ``DateObject`` : ```wl In[1]:= EntityValue[Entity["AstronomicalRadioSource", "SagittariusAStar"], EntityProperty["AstronomicalRadioSource", "DistanceFromEarth", {"Date" -> #}]& /@ {DateObject[{2014, 4, 9, 22, 0, 0}, "Instant", "Gregorian", -5.], \[FreeformPrompt]["birth date of Michael Jackson"]}] Out[1]= {Quantity[26673.0685696752698277123`2.50519051558078, "LightYears"], Quantity[26673.0685696752698277123`2.50519051558078, "LightYears"]} ``` Date qualifiers can also be specified using ``Dated`` : ```wl In[2]:= EntityValue[Entity["AstronomicalRadioSource", "SagittariusAStar"], Dated["DistanceFromEarth", #]& /@ {DateObject[{2014, 4, 9, 22, 0, 0}, "Instant", "Gregorian", -5.], \[FreeformPrompt]["birth date of Michael Jackson"]}] Out[2]= {Quantity[26673.0685696752698277123`2.50519051558078, "LightYears"], Quantity[26673.0685696752698277123`2.50519051558078, "LightYears"]} ``` ## See Also * [`BlackHole`](https://reference.wolfram.com/language/ref/entity/BlackHole.en.md) * [`Galaxy`](https://reference.wolfram.com/language/ref/entity/Galaxy.en.md) * [`Star`](https://reference.wolfram.com/language/ref/entity/Star.en.md) * [`StarCluster`](https://reference.wolfram.com/language/ref/entity/StarCluster.en.md) * [`Nebula`](https://reference.wolfram.com/language/ref/entity/Nebula.en.md) * [`Supernova`](https://reference.wolfram.com/language/ref/entity/Supernova.en.md) * [`Pulsar`](https://reference.wolfram.com/language/ref/entity/Pulsar.en.md) * [`Constellation`](https://reference.wolfram.com/language/ref/entity/Constellation.en.md) * [`AstronomicalRadioSource`](https://reference.wolfram.com/language/ref/interpreter/AstronomicalRadioSource.en.md) * [`ComputedAstronomicalRadioSource`](https://reference.wolfram.com/language/ref/interpreter/ComputedAstronomicalRadioSource.en.md) * [`BlackHole`](https://reference.wolfram.com/language/ref/interpreter/BlackHole.en.md) * [`BlackHoleClass`](https://reference.wolfram.com/language/ref/interpreter/BlackHoleClass.en.md) * [`AstronomicalRadioSource`](https://reference.wolfram.com/language/ref/textcontent/AstronomicalRadioSource.en.md) ## Related Guides * [Entity Types](https://reference.wolfram.com/language/guide/EntityTypes.en.md) ## Related Links * [AstronomicalRadioSource Source Information](http://www.wolfram.com/knowledgebase/source-information/?page=AstronomicalRadioSourceData) ## History * [Introduced in 2019 (12.0)](https://reference.wolfram.com/language/guide/SummaryOfNewFeaturesIn120.en.md)