METALLICITY-DEPENDENT STELLAR AGES AND THE G-DWARF PROBLEM

We report on a study of the distribution of low-metallicity stars in the Galactic disk. This study makes use of model calculations which include the effects of changing metal and helium abundances on stellar lifetimes. Since low-metallicity stars have shorter main-sequence lifetimes than their Population I counterparts, there are fewer metal-poor G dwarfs at the present time than expected from calculations using lifetimes for stars with a solar composition. Inclusion of these metal-dependent lifetimes is shown to somewhat alleviate the G dwarf problem.