SLA_RVLSRK

RV Corrn to Kinematical LSR

ACTION:
Velocity component in a given direction due to the Sun’s motion with respect to a kinematical Local Standard of Rest.
CALL:
R = sla_RVLSRK (R2000, D2000)
GIVEN:

R2000,D2000

R

J2000.0 mean [α, δ] (radians)


RETURNED:

sla_RVLSRK

R

Component of standard solar motion in direction R2000,D2000 (km s1)


NOTES:
(1)
Sign convention: the result is positive when the Sun is receding from the given point on the sky.
(2)
The Local Standard of Rest used here is one of several kinematical LSRs in common use. A kinematical LSR is the mean standard of rest of specified star catalogues or stellar populations. The Sun’s motion with respect to a kinematical LSR is known as the standard solar motion.
(3)
There is another sort of LSR, seldom used by observational astronomers, called the dynamical LSR. This is a point in the vicinity of the Sun which is in a circular orbit around the Galactic centre. The Sun’s motion with respect to the dynamical LSR is called the peculiar solar motion. To obtain a radial velocity correction with respect to the dynamical LSR use the routine sla_RVLSRD.
(4)
The adopted standard solar motion is 20 km s1 towards α = 18h, δ = +30 (1900).
REFERENCES:
(1)
Delhaye (1965), in Stars and Stellar Systems, vol 5, p73.
(2)
Methods of Experimental Physics (ed Meeks), vol 12, part C, sec 6.1.5.2, p281.