Problem: Consider an O3 star of 50 M? and 106 L? when it has reached oxygen burning. Assume that O burning produces one tenth the energy per gram of fuel that H burning does and that the star burns 3 solar masses of oxygen. Also assume for simplicity that all the star's energy is produced by oxygen burning.
A) If O burning lasts two months, what is the neutrino energy loss rate in erg/g/s?
B) What fraction of the energy produced by O burning is lost as neutrinos?