GeocentricMeanEcliptic#
- class astropy.coordinates.GeocentricMeanEcliptic(*args, copy=True, representation_type=None, differential_type=None, **kwargs)[source]#
Bases:
BaseEclipticFrame
Geocentric mean ecliptic coordinates. These origin of the coordinates are the geocenter (Earth), with the x axis pointing to the mean (not true) 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.
- Parameters:
- data
BaseRepresentation
subclass instance A representation object or
None
to have no data (or use the coordinate component arguments, see below).- lon
Angle
, optional, keyword-only The ecliptic longitude for this object (
lat
must also be given andrepresentation
must be None).- lat
Angle
, optional, keyword-only The ecliptic latitude for this object (
lon
must also be given andrepresentation
must be None).- distance
Quantity
[:ref: ‘length’], optional, keyword-only The distance for this object from the geocenter. (
representation
must be None).- pm_lon_coslat
Quantity
[‘angualar speed’], optional, keyword-only The proper motion in the ecliptic longitude (including the
cos(lat)
factor) for this object (pm_lat
must also be given).- pm_lat
Quantity
[:ref: ‘angular speed’], optional, keyword-only The proper motion in the ecliptic latitude for this object (
pm_lon_coslat
must also be given).- radial_velocity
Quantity
[:ref: ‘speed’], optional, keyword-only The radial velocity of this object.
- representation_type
BaseRepresentation
subclass,str
, optional A representation class or string name of a representation class. This sets the expected input representation class, thereby changing the expected keyword arguments for the data passed in. For example, passing
representation_type='cartesian'
will make the classes expect position data with cartesian names, i.e.x, y, z
in most cases unless overridden viaframe_specific_representation_info
. To see this frame’s names, check out<this frame>().representation_info
.- differential_type
BaseDifferential
subclass,str
,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_type='cartesian'
will make the classes expect velocity data with the argument namesv_x, v_y, v_z
unless overridden viaframe_specific_representation_info
. To see this frame’s names, check out<this frame>().representation_info
.- copybool, optional
If
True
(default), make copies of the input coordinate arrays. Can only be passed in as a keyword argument.
- data
- 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.
- obstime
Time
, optional The time at which the observation is taken. Used for determining the position of the Earth. Defaults to J2000.
- equinox
Attributes Summary
Default representation for differential data (e.g., velocity)
Default representation for position data
The equinox time
Mapping for frame-specific component names
The reference time (e.g., time of observation)
Attributes Documentation
- default_differential#
Default representation for differential data (e.g., velocity)
- default_representation#
Default representation for position data
- equinox#
The equinox time
Default: J2000.000
- frame_attributes = {'equinox': <astropy.coordinates.attributes.TimeAttribute object>, 'obstime': <astropy.coordinates.attributes.TimeAttribute object>}#
- frame_specific_representation_info#
Mapping for frame-specific component names
- name = 'geocentricmeanecliptic'#
- obstime#
The reference time (e.g., time of observation)
Default: J2000.000