Convection and convective overshooting in stars more massive than 10 M⊙

Abstract

Abstract We examine how the mixing length parameter αp and the overshooting parameter δov affect the properties of convective cores and convective envelopes in stars more massive than 10 M⊙. First, we show that a larger value of αp leads to a stronger mixing, a smaller chemical gradient, a higher effective temperature, and a smaller stellar radius. We then find that if a star develops convective core overshooting during the main sequence phase, the star will enter the red (super)giant phase earlier than a star without core overshooting. Finally, we find that a convective envelope leads to a discontinuity of the hydrogen profile above the hydrogen burning shell. Convective envelope overshooting can facilitate the occurrence of blue loop in the Hertzsprung–Russell diagram.