On the Theory of Evolution of Completely Mixed Stars with Mass Loss

The consequences of substituting the $$\mathfrak {M}-L-\mu$$ (mass–luniinosity–mean molecular weight) relation of stellar structure theory in place of the ‘empirical’ $$\mathfrak {M}-L$ and $$\mathfrak {M}-\mu$$ relations are investigated for the Russian theory of evolution of completely mixed stars with mass loss. The mass loss rate becomes a free parameter, but stars still evolve along the main sequence. It is found that by theoretically evolving the initial luminosity function, the observed luminosity functions of early-type galactic clusters may be reasonably well reproduced with a variety of mass loss rates and ages. Hence the luminosity function per se does not give definite evidence for the mode of stellar evolution (homogeneous or inhomogeneous), rate of mass loss, or age of a cluster.