galpy.orbit.Orbit.ll¶
- Orbit.ll(*args, **kwargs)[source]¶
NAME:
ll
PURPOSE:
return Galactic longitude
INPUT:
t - (optional) time at which to get ll
- obs=[X,Y,Z] - (optional) position of observer (in kpc)
(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= distance in kpc corresponding to R=1. (default=Object-wide default)
OUTPUT:
l(t) [*input_shape,nt]
HISTORY:
2019-02-21 - Written - Bovy (UofT)