Convection and convective overshooting in stars more massive than 10 $M_\odot$

TL;DR

This study investigates how different mixing length and overshooting parameters affect the internal structure and evolution of stars more massive than 10 solar masses, revealing key factors influencing convective processes and stellar evolution paths.

Contribution

It provides new insights into the impact of mixing length and overshooting parameters on convective properties and evolutionary outcomes of massive stars.

Findings

Larger mixing length enhances convective mixing and heat transfer.

Core potential effectively describes stellar evolution stages.

Hydrogen profile discontinuity influences blue loop occurrence.

Abstract

In this paper, four sets of evolutionary models are computed with different values of the mixing length parameter $\alpha_{\rm p}$ and the overshooting parameter $\delta_{\rm ov}$. The properties of the convective cores and the convective envelopes are studied in the massive stars. We get three conclusions: First, the larger $\alpha_{\rm p}$ leads to enhancing the convective mixing, removing the chemical gradient, and increasing the convective heat transfer efficiency. Second, core potential $\phi_{\rm c} = M_{\rm c} / R_{\rm c}$ describes sufficiently the evolution of a star, whether it is a red or blue supergiant at central helium ignition. Third, the discontinuity of hydrogen profile above the hydrogen burning shell seriously affect the occurrence of blue loops in the Hertzsprung--Russell diagram.