NAME:
pmllPURPOSE:
return proper motion in Galactic longitude (in mas/yr)INPUT:
t - (optional) time at which to get pmll
(in kpc and km/s) (default=[8.0,0.,0.,0.,220.,0.]) OR Orbit object that corresponds to the orbit of the observerro= distance in kpc corresponding to R=1. (default: 8.0)
vo= velocity in km/s corresponding to v=1. (default: 220.)
OUTPUT:
pm_l(t)
HISTORY:
2011-02-24 - Written - Bovy (NYU)