Behaviour of Pulsations in Hydrodynamic Models of Massive Stars

TL;DR

This paper investigates pulsation behaviors in massive stars using nonlinear hydrodynamic models with time-dependent convection, revealing long-period pulsations and outburst-like phenomena in stars of 40-85 solar masses.

Contribution

It introduces detailed hydrodynamic models of massive stars that incorporate time-dependent convection to study pulsation behaviors and mass-loss phenomena.

Findings

Models exhibit long-period pulsations over 100 days.

Some models show outburst-like behavior.

Calculated wind mass-loss rates during pulsations.

Abstract

We have calculated the pulsations of massive stars using a nonlinear hydrodynamic code including time-dependent convection. The basic structure models are based on a standard grid published by Meynet et al. (1994). Using the basic structure, we calculated envelope models, which include the outer few percent of the star. These models go down to depths of at least 2 million K. These models, which range from 40 to 85 solar masses, show a range of pulsation behaviours. We find models with very long period pulsations ( $>$ 100 d), resulting in high amplitude changes in the surface properties. We also find a few models that show outburst-like behaviour. The details of this behaviour are discussed, including calculations of the resulting wind mass-loss rates.