galpy.orbit.Orbit.vra¶
- Orbit.vra(*args, **kwargs)[source]¶
Return velocity in right ascension (km/s).
- Parameters:
t (numeric, numpy.ndarray or Quantity, optional) – Time at which to get vra. 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.
vo (float or Quantity, optional) – Physical scale for velocities in km/s 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.
- Returns:
v_ra(t) in km/s.
- Return type:
numpy.ndarray or Quantity [*input_shape]
Notes
2019-02-28 - Written - Bovy (UofT)