GeocentricTrueEcliptic

class astropy.coordinates.GeocentricTrueEcliptic(*args, **kwargs)

Bases: astropy.coordinates.BaseEclipticFrame

Geocentric ecliptic coordinates. These origin of the coordinates are the geocenter (Earth), with the x axis pointing to the true (not mean) equinox at the time specified by the equinox attribute, and the xy-plane in the plane of the ecliptic for that date.

Be aware that the definition of “geocentric” here means that this frame includes light deflection from the sun, aberration, etc when transforming to/from e.g. ICRS.

The frame attributes are listed under Other Parameters.

Warning

In the current version of astropy, the ecliptic frames do not yet have stringent accuracy tests. We recommend you test to “known-good” cases to ensure this frames are what you are looking for. (and then ideally you would contribute these tests to Astropy!)

Parameters:

representation : BaseRepresentation or None

A representation object or None to have no data (or use the other keywords)

lon : Angle, optional, must be keyword

The ecliptic longitude for this object (lat must also be given and representation must be None).

lat : Angle, optional, must be keyword

The ecliptic latitude for this object (lon must also be given and representation must be None).

distance : Quantity, optional, must be keyword

The distance for this object from the geocenter. (representation must be None).

pm_lon_coslat : Angle, optional, must be keyword

The proper motion in the ecliptic longitude (including the cos(lat) factor) for this object (pm_lat must also be given).

pm_lat : Angle, optional, must be keyword

The proper motion in the ecliptic latitude for this object (pm_lon_coslat must also be given).

distance : Quantity, optional, must be keyword

The distance for this object from the geocenter. (representation must be None).

copy : bool, optional

If True (default), make copies of the input coordinate arrays. Can only be passed in as a keyword argument.

differential_cls : BaseDifferential, dict, optional

A differential class or dictionary of differential classes (currently only a velocity differential with key ‘s’ is supported). This sets the expected input differential class, thereby changing the expected keyword arguments of the data passed in. For example, passing differential_cls=CartesianDifferential will make the classes expect velocity data with the argument names v_x, v_y, v_z.

Other Parameters:  

equinox : Time, optional

The date to assume for this frame. Determines the location of the x-axis and the location of the Earth (necessary for transformation to non-geocentric systems). Defaults to the ‘J2000’ equinox.

Attributes Summary

default_differential
default_representation
equinox
frame_attributes
frame_specific_representation_info
name

Attributes Documentation

default_differential

default_representation

equinox = <Time object: scale='utc' format='jyear_str' value=J2000.000>

frame_attributes = {'equinox': <astropy.coordinates.attributes.TimeAttribute object at 0xadd6f670>}

frame_specific_representation_info

name = 'geocentrictrueecliptic'