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AstroProjection

is an option of AstroGraphics that specifies the cartographic projection to use for the map.

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AstroProjection

AstroProjection

is an option of AstroGraphics that specifies the cartographic projection to use for the map.

Details

  • In an AstroGraphics map of the sky, the option AstroReferenceFrame selects the orientation and location of the axes defining spherical coordinates. The option AstroProjection then selects how those coordinates are projected onto a 2D plane.
  • AstroProjection can use any projection "proj" or {"proj",params}, where "proj" is any of the entities of GeoProjectionData and params are parameter rules like "StandardParallels"{33,60}. GeoProjectionData["proj"] gives the default values of the parameters for the projection "proj".
  • AstroGraphics[…,AstroProjectionAutomatic] chooses a projection automatically. It will be "Stereographic" for small or intermediate scales, while the choice for large scales will depend on the astro reference frame being used.
  • AbsoluteOptions can be used to give explicit projection information for a map built with AstroProjection having Automatic value in input.

Examples

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Basic Examples  (3)

AstroGraphics uses by default a stereographic projection for maps of small and intermediate scales:

Wolfram Language code: AstroGraphics[Entity["Star", "Mizar"], AstroRange -> Quantity[15, "AngularDegrees"]]
Wolfram Language code: Options[%, AstroProjection]

Maps of the whole sky in equatorial coordinates are shown by default in the equirectangular projection:

Wolfram Language code: AstroGraphics[AstroRange -> All, AstroReferenceFrame -> "Equatorial"]

Maps of the whole sky in galactic coordinates are shown by default in the Mollweide projection:

Wolfram Language code: AstroGraphics[AstroRange -> All, AstroReferenceFrame -> {"Galactic", Here}]

Use another azimuthal projection instead:

Wolfram Language code: AstroGraphics[AstroRange -> {All, All}, AstroRangePadding -> None, AstroReferenceFrame -> {"Galactic", Here}, AstroProjection -> "LambertAzimuthal", ImageSize -> Medium]

Scope  (2)

Perform projections with default or automatic parameters:

Wolfram Language code: AstroGraphics[{Entity["Star", "Arcturus"], Entity["Star", "Sirius"]}, AstroReferenceFrame -> "Equatorial", AstroRangePadding -> 15]

Find out which projection was used:

Wolfram Language code: AbsoluteOptions[%, AstroProjection]

Specify your own projection and parameters:

Wolfram Language code: AstroGraphics[{Entity["Star", "Arcturus"], Entity["Star", "Sirius"]}, AstroProjection -> {"LambertAzimuthal", "Centering" -> {0, 180}}, AstroReferenceFrame -> "Equatorial", AstroRangePadding -> 10]
Wolfram Research (2022), AstroProjection, Wolfram Language function, https://reference.wolfram.com/language/ref/AstroProjection.html.

Text

Wolfram Research (2022), AstroProjection, Wolfram Language function, https://reference.wolfram.com/language/ref/AstroProjection.html.

CMS

Wolfram Language. 2022. "AstroProjection." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/AstroProjection.html.

APA

Wolfram Language. (2022). AstroProjection. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/AstroProjection.html

BibTeX

@misc{reference.wolfram_2026_astroprojection, author="Wolfram Research", title="{AstroProjection}", year="2022", howpublished="\url{https://reference.wolfram.com/language/ref/AstroProjection.html}", note=[Accessed: 12-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_astroprojection, organization={Wolfram Research}, title={AstroProjection}, year={2022}, url={https://reference.wolfram.com/language/ref/AstroProjection.html}, note=[Accessed: 12-June-2026]}