1. The only information that can be determined about the masses m 1 and m 2 of the two components of a spectroscopic binary when the spectral lines of only one component (of mass m 1) can be observed. It is equal to
(m 2 3 sin3 i )/(m 1 + m 2 )2where m 1 and m 2 are measured in solar masses and i is the inclination of the orbit.
2. (Salpeter mass function) See stellar mass.