# ICRS¶

class astropy.coordinates.ICRS(*args, **kwargs)[source] [edit on github]

A coordinate or frame in the ICRS system.

If you’re looking for “J2000” coordinates, and aren’t sure if you want to use this or FK5, you probably want to use ICRS. It’s more well-defined as a catalog coordinate and is an inertial system, and is very close (within tens of milliarcseconds) to J2000 equatorial.

For more background on the ICRS and related coordinate transformations, see the references provided in the See Also section of the documentation.

Parameters: representation : BaseRepresentation or None A representation object or None to have no data (or use the other keywords) ra : Angle, optional, must be keyword The RA for this object (dec must also be given and representation must be None). dec : Angle, optional, must be keyword The Declination for this object (ra must also be given and representation must be None). distance : Quantity, optional, must be keyword The Distance for this object along the line-of-sight. (representation must be None).

Attributes Summary

Attributes Documentation

default_representation
frame_specific_representation_info
name = 'icrs'