Mass loss of red supergiants: a key ingredient for the final evolution of massive stars

TL;DR

This paper discusses how uncertain mass-loss rates in red supergiants significantly influence the final evolutionary paths of massive stars, affecting whether they end as red or blue supergiants.

Contribution

It provides a summary of the effects and uncertainties of mass loss during the red supergiant phase on stellar evolution.

Findings

Mass-loss rates are highly uncertain and can be very high.

Mass loss impacts whether stars end as red or blue supergiants.

Uncertainties affect the population of blue supergiant stars.

Abstract

Mass-loss rates during the red supergiant phase are very poorly constrained from an observational or theoretical point of view. However, they can be very high, and make a massive star lose a lot of mass during this phase, influencing considerably the final evolution of the star: will it end as a red supergiant? Will it evolve bluewards by removing its hydrogen-rich envelope? In this paper, we briefly summarise the effects of this mass loss and of the related uncertainties, particularly on the population of blue supergiant stars.