Orbit.helioX(*args, **kwargs)[source]

Return Heliocentric Galactic rectangular x-coordinate (aka “X”).

  • t (numeric, numpy.ndarray or Quantity, optional) – Time at which to get X. Default is the initial time.

  • obs (numpy.ndarray, Quantity or Orbit, optional) – Position and velocity of observer in the Galactocentric frame (in kpc and km/s) (default=object-wide default) OR Orbit object that corresponds to the orbit of the observer. Note that when Y is non-zero, the coordinate system is rotated around z such that Y’=0.

  • ro (float or Quantity, optional) – Physical scale in kpc for distances to use to convert. Default is object-wide default.

  • use_physical (bool, optional) – Use to override object-wide default for using a physical scale for output.

  • quantity (bool, optional) – If True, return an Astropy Quantity object. Default from configuration file.


helioX(t) in kpc.

Return type:

float, numpy.ndarray or Quantity [*input_shape,nt]


  • 2019-02-21 - Written - Bovy (UofT)