Equatorial mass loss from Be stars

TL;DR

This paper uses improved stellar evolution models to estimate equatorial mass loss rates in fast rotating Be stars, enhancing understanding of disc formation and star evolution.

Contribution

It introduces a new grid of models for fast rotating B stars to estimate mass loss during the critical rotation phase.

Findings

Initial estimates of total mass loss during critical rotation.

Mechanical mass loss rates in equatorial discs.

Evolutionary pathways towards the Be phase.

Abstract

Be stars are thought to be fast rotating stars surrounded by an equatorial disc. The formation, structure and evolution of the disc are still not well understood. In the frame of single star models, it is expected that the surface of an initially fast rotating star can reach its keplerian velocity (critical velocity). The Geneva stellar evolution code has been recently improved, in order to obtain some estimates of the total mass loss and of the mechanical mass loss rates in the equatorial disc during the whole critical rotation phase. We present here the first results of the computation of a grid of fast rotating B stars evolving towards the Be phase, and discuss the first estimates we obtained.