METAL OPACITIES AND CONVECTIVE CORE OVERSHOOTING IN POPULATION-I STARS

New stellar opacities computed by Rogers and Iglesias are found to lead to revised evolutionary models for stars of intermediate to high mass that show remarkably close agreement with observed stars, under otherwise standard physical assumptions. Most or all of the earlier discrepancies, except for the problem of predicted apsidal motion constants that are perhaps still too large, appear to have been resolved by using these new opacities with their increased metal line contribution. Thus, the implied interior metallicity of massive stars in the solar neighborhood now becomes "normal." Furthermore, the effective distance of convective overshooting beyond the classical convective core boundary is confirmed to be small and probably less than 0.2 times the local pressure scale height.