Mass loss and the Eddington parameter

TL;DR

This paper extends stellar wind theory to very massive stars, providing a new mass-loss prescription that explains empirical data and can be integrated into stellar evolution models, especially for stars with high Eddington parameters.

Contribution

It introduces a new mass-loss description for very massive stars that accounts for optically thick winds and aligns with empirical observations, improving stellar evolution modeling.

Findings

The new model explains the empirical mass-loss dependence on the Eddington parameter.

Derived a mass-loss recipe for the Large Magellanic Cloud.

The prescription is suitable for incorporation into stellar evolution codes.

Abstract

Mass loss through stellar winds plays a dominant role in the evolution of massive stars. Very massive stars (VMSs, $> 100 M_{\odot}$) display Wolf-Rayet spectral morphologies (WNh) whilst on the main-sequence. Bestenlehner (2020) extended the elegant and widely used stellar wind theory by Castor, Abbott & Klein (1975) from the optically thin (O star) to the optically thick main-sequence (WNh) wind regime. The new mass-loss description is able to explain the empirical mass-loss dependence on the Eddington parameter and is suitable for incorporation into stellar evolution models for massive and very massive stars. The prescription can be calibrated with the transition mass-loss rate defined in Vink & Gr\"afener (2012). Based on the stellar sample presented in Bestenlehner et al. (2014) we derive a mass-loss recipe for the Large Magellanic Cloud using the new theoretical mass-loss prescription of Bestenlehner (2020).