GalacticCoordinates

class astropy.coordinates.builtin_systems.GalacticCoordinates(*args, **kwargs)

Bases: astropy.coordinates.coordsystems.SphericalCoordinatesBase

A coordinate in Galactic Coordinates.

Note

Transformations from Galactic Coordinates to other systems are not well-defined because of ambiguities in the definition of Galactic Coordinates. See Lie et al. 2011 for more details on this. Here, we use the Reid & Brunthaler 2004 definition for converting to/from FK5, and assume the IAU definition applies for converting to FK4 without e-terms.

Parameters :

coordstr : str

A single string with the coordinates. Cannot be used with b and l nor x/y/z.

l : Angle, float, int, str

This must be given with b.

b : Angle, float, int, str

This must be given with l.

distance : Distance, optional

This may be given with b and l or coordstr and not x, y, or z. If not given, None (unit sphere) will be assumed.

x : number

The first cartesian coordinate. Must be given with y and z and not with l or b nor coordstr.

y : number

The second cartesian coordinate. Must be given with x and z and not with l or b nor coordstr.

z : number

The third cartesian coordinate. Must be given with x and y and not with l or b nor coordstr.

cartpoint : CartesianPoints

A cartesian point with the coordinates. Cannot be used with any other arguments.

unit :

The unit parameter’s interpretation depends on what other parameters are given:

• If l and b or coordstr are given:

  unit must be a length-2 sequence specifying the units of l and b, respectively. They can be either UnitBase objects or strings that will be converted using Unit. They can also be None to attempt to automatically interpret the units (see Angle for details.) If unit is just None, this will be interpreted the same as (None, None).

• If x, y, and z are given:

  unit must be a single unit with dimensions of length

obstime : Time or None

The time of observation for this coordinate. If None, it will be taken to be the same as the equinox.

Alternatively, a single argument that is any kind of spherical coordinate :

can be provided, and will be converted to `GalacticCoordinates` and :

used as this coordinate. :

Attributes Summary

lonangle
latangle

Attributes Documentation

lonangle

latangle