How can you estimate mass of star?

[dsisk559]

Is there a way to estimate the mass of a star using Spectral Class and absolute magnitude?

If you can't then what info do I need in order to so.

Thanks,
Dan

[mgb_phys]

From the absolute magnitude and the luminosity magnitude relationship you can pretty easily get the mass of a main sequence star.
L = M ^ 3.5 ( with L and M relative to the sun)

For larger or smaller stars there is a different exponent and sometimes slightly more complex relationship.