HeliocentricEclipticIAU76

class astropy.coordinates.HeliocentricEclipticIAU76(*args, copy=True, representation_type=None, differential_type=None, **kwargs)[source]

Bases: astropy.coordinates.BaseEclipticFrame

Heliocentric mean (IAU 1976) ecliptic coordinates. These origin of the coordinates are the center of the sun, with the x axis pointing in the direction of the mean (not true) equinox of J2000, and the xy-plane in the plane of the ecliptic of J2000 (according to the IAU 1976/1980 obliquity model). It has, therefore, a fixed equinox and an older obliquity value than the rest of the frames.

The frame attributes are listed under Other Parameters.

{params}

Parameters
dataBaseRepresentation subclass instance

A representation object or None to have no data (or use the coordinate component arguments, see below).

lonAngle, optional, keyword-only

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

latAngle, optional, keyword-only

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

distanceQuantity [:ref: ‘length’], optional, keyword-only

The distance for this object from the sun’s center. (representation must be None).

pm_lon_coslatQuantity [‘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_latQuantity [:ref: ‘angular speed’], optional, keyword-only

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

radial_velocityQuantity [:ref: ‘speed’], optional, keyword-only

The radial velocity of this object.

representation_typeBaseRepresentation 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 via frame_specific_representation_info. To see this frame’s names, check out <this frame>().representation_info.

differential_typeBaseDifferential 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 names v_x, v_y, v_z unless overridden via frame_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.

Attributes Summary

default_differential

Default representation for differential data (e.g., velocity)

default_representation

Default representation for position data

frame_attributes

frame_specific_representation_info

Mapping for frame-specific component names

name

obstime

Attributes Documentation

default_differential

Default representation for differential data (e.g., velocity)

default_representation

Default representation for position data

frame_attributes = {'obstime': <astropy.coordinates.attributes.TimeAttribute object>}
frame_specific_representation_info

Mapping for frame-specific component names

name = 'heliocentriceclipticiau76'
obstime = <Time object: scale='tt' format='jyear_str' value=J2000.000>