Astrophysical constraints on a new light axion and other weakly interacting particles

Constraints on the light axion of Dine, Fischler, and Srednicki are critically reexamined and upper bounds on its mass are derived from stars at various stages of evolution. A conservative upper bound for the axion mass is about 1 eV, while a model-dependent argument gives a better upper bound of mass ∼0.07 eV. The same argument also applies to coupling of any massless pseudoscalar particle to electrons giving an upper bound of $\left|g_e\right|<\mathrm{}1\mathrm{}\times {10}^{-11\mathrm{}}$.