Yellow Hypergiants as Dynamically Unstable Post-Red Supergiant Stars
Abstract
According to recent theoretical studies, the majority of single stars more massive than 30 Msolar successfully evolve into red supergiants but then lose most of their hydrogen envelopes and metamorphose into hot blue remnants. While they are cool, they become dynamically unstable as a result of high radiation pressure and partial ionization of the gases in their outer layers. It is shown here that these unstable red supergiant models repeatedly shrink and reexpand on a thermal timescale when perturbed by heavy bursts of mass loss. Consequently, they fill up the domain of yellow hypergiants on the Hertzsprung-Russell diagram and display very fast rates of evolution there, as observed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 2001
- DOI:
- 10.1086/322438
- Bibcode:
- 2001ApJ...560..934S
- Keywords:
-
- Stars: Evolution;
- Stars: Mass Loss;
- Stars: Oscillations;
- Stars: Variables: Other