Velocity of a star for Doppler Spectroscopy

[skydivephil]

Im trying to solve back for Jupiters effect on the suns orbital velocity. Ive looked up the asnwer and its 12.7 m/s
and the formula I have for this is
http://en.wikipedia.org/wiki/Doppler_spectroscopy

v = SQR (Gm*/r)
where G is Grav constant
M is the mass of the star (planets mass is negligible )
r is the diatcen of the Jupiter sun distance
I have g as 6.673*10^-11
I have the suns mass as 1.989*10^30
I have r as 7.8*10^11
This gives me Gm as 1.32*10^20
so Gm/r = 1.7*10^8
and the square rot of that is 13044. so why did I get 13044 and not the value of 12.7?

Can anyone help?

[Vagn]

Jupiter's orbital speed is about 13.07 km/s not or 13070 m/s so you did actually get the right answer.

http://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html

[skydivephil]

Jupiter's orbital speed is about 13.07 km/s not or 13070 m/s so you did actually get the right answer.

http://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html

Thanks for that