Source code for astropy.coordinates.builtin_frames.cirs
# Licensed under a 3-clause BSD style license - see LICENSE.rst
from astropy.coordinates.attributes import EarthLocationAttribute, TimeAttribute
from astropy.coordinates.baseframe import base_doc
from astropy.utils.decorators import format_doc
from .baseradec import BaseRADecFrame, doc_components
from .utils import DEFAULT_OBSTIME, EARTH_CENTER
__all__ = ["CIRS"]
doc_footer = """
Other parameters
----------------
obstime : `~astropy.time.Time`
The time at which the observation is taken. Used for determining the
position of the Earth and its precession.
location : `~astropy.coordinates.EarthLocation`
The location on the Earth. This can be specified either as an
`~astropy.coordinates.EarthLocation` object or as anything that can be
transformed to an `~astropy.coordinates.ITRS` frame. The default is the
centre of the Earth.
"""
[docs]@format_doc(base_doc, components=doc_components, footer=doc_footer)
class CIRS(BaseRADecFrame):
"""
A coordinate or frame in the Celestial Intermediate Reference System (CIRS).
The frame attributes are listed under **Other Parameters**.
"""
obstime = TimeAttribute(default=DEFAULT_OBSTIME)
location = EarthLocationAttribute(default=EARTH_CENTER)
# The "self-transform" is defined in icrs_cirs_transformations.py, because in
# the current implementation it goes through ICRS (like GCRS)