Follow the link below,

http://www.newscientist.com/article/dn9336

Basically, they can calculate the massive of a gas giant's moon with that method, so, why can't they use a similar model and apply it to stars?

They have plenty of extra solar systems to choose from and to predict if that system's accurate.

Note: Stellar composition will effect planetary mass, i.e. Metallicity.


Or have they already?