Hot Star Winds

TL;DR

Hot star winds are a complex, widespread phenomenon crucial for understanding massive star evolution, influenced by spectral line opacities, metallicity, and recent advances in hydrodynamic modeling, especially for Wolf-Rayet stars.

Contribution

This paper reviews the current understanding of hot star winds, highlighting recent progress in hydrodynamic models and their implications for massive star evolution.

Findings

Hot star winds are driven by spectral line opacities and vary with metallicity.

Recent hydrodynamic models improve understanding of Wolf-Rayet star mass loss.

Wind properties significantly influence the evolution of massive stars.

Abstract

The properties, impact, and fate of hot stars cannot be understood without considering their winds. Revealed to be an almost ubiquitous phenomenon in the regime of massive stars, the winds of hot stars arise from a complex physical mechanism that still provides a major challenge for our understanding of massive stars. Different flavours of hot stars vary significantly in their winds with current evolution models still having problems to connect the zoo of observed phenomena. Moreover, the driving of hot star winds is inherently connected to the opacities arising from spectral line transitions, making the properties and strength of the winds strongly dependent on metallicity and changing them over cosmic time. In these proceedings, the current status in our understanding of hot star winds is briefly reviewed and recent progress in our perception of hot star winds and the consequences for the evolution of massive stars are presented. A particular emphasis is given on current efforts with hydrodynamically-consistent atmosphere models towards a better description of radiatively-driven mass loss of Wolf-Rayet stars with remaining hydrogen envelopes.