Velocity component in a given direction due to the combination of the rotation of
the Galaxy and the motion of the Galaxy relative to the mean motion of the local group.
CALL:
R = sla_RVLG (R2000, D2000)
GIVEN:
R2000,D2000
R
J2000.0 mean [α,δ] (radians)
RETURNED:
sla_RVLG
R
Component of solar (n.b.)
motion in direction R2000,D2000
(km s−1)
NOTE:
Sign convention: the result is positive when the Sun is receding from the given point
on the sky.