Calculating Radial Velocity from Hipparcos Using data from Hipparcos is it possible to calculate Radial Velocity.  If we take 19 Leonis as example, RV is -3.70.  Is it calculated from Proper Motion?  Can I ask that any formulas be done in long hand please, i.e. how you would enter it into a standard spreadsheet rather than with symbols etc.

http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=19+Leonis&amp;submit=SIMBAD+search

Additionally

Took the advice and found CRVAD2.dat ( http://cdsarc.u-strasbg.fr/viz-bin/Cat?III/254 ).  The following line comes from CRVAD2.dat file and when I looked up HipId 40829 which is below, the RV value is -3.70 which matches the link above.  

9.790554129  11.56817726   0.8   0.1   11.06   1.00   -48.63    -3.39   1.24   0.69  6.709  6.436 0.005 0.005 0.007   D   AY D A3n          A 7 VN                48029  84722  948942 4 ABA    -3.70  -9.99 B   9 1


If I look up Sirius (32349), it says the RV is -7.60 but when you look up Sirius at Simbad, it says -5.50 ( http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=Sirius ) 

6.752569403 -16.71314306   1.2   0.1  379.20   1.58  -552.63 -1206.40   0.50   0.50 -1.430 -1.121 0.011 0.002 0.039   U     OD A1V+A5wd     A1V+A5wd              32349  48915 1447791 4 AB     -7.60  -9.99 A   0 1


Whats the reason for the discrepancy, CRVAD2.dat is an old version like there's two Hip data files (97 and 07)?
You cannot calculate the radial velocity from a proper motion. The proper motion is the motion you see the star move on the sky, so perpendicular to your line of sight towards the star. The radial velocity is the velocity of the star along this line of sight. Perhaps this picture will help:


https://en.wikipedia.org/wiki/Proper_motion

Radial velocities are actually calculated by measuring the Doppler shift of the spectra of stars, but this is not very easy, and you need the raw spectrum data. You are probably best off just taking the values of the radial velocity from that site for example.