The stability of massive main-sequence stars as a function of metallicity

Joshua H. Shiode, Eliot Quataert, Phil Arras

Research output: Contribution to journalArticle

5 Scopus citations

Abstract

We investigate the pulsational stability of massive (M≳ 120M ) main-sequence stars of a range of metallicities, including primordial, Population III stars. We include a formulation of convective damping motivated by numerical simulations of the interaction between convection and periodic shear flows. We find that convective viscosity is likely strong enough to stabilize radial pulsations whenever nuclear burning (the ε-mechanism) is the dominant source of driving. This suggests that massive main-sequence stars with Z≲ 2 × 10 -3 are pulsationally stable and are unlikely to experience pulsation-driven mass loss on the main sequence. These conclusions are, however, sensitive to the form of the convective viscosity and highlight the need for further high-resolution simulations of the convection-oscillation interaction. For more metal-rich stars (Z≳ 2 × 10 -3), the dominant pulsational driving arises due to the κ-mechanism arising from the iron-bump in opacity and is strong enough to overcome convective damping. Our results highlight that even for oscillations with periods a few orders of magnitude shorter than the outer convective turnover time, the 'frozen-in' approximation for the convection-oscillation interaction is inappropriate, and convective damping should be taken into account when assessing mode stability.

Original languageEnglish (US)
Pages (from-to)3397-3404
Number of pages8
JournalMonthly Notices of the Royal Astronomical Society
Volume423
Issue number4
DOIs
StatePublished - Jul 2012

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Keywords

  • Stars: Population III
  • Stars: massive
  • Stars: oscillations

Fingerprint Dive into the research topics of 'The stability of massive main-sequence stars as a function of metallicity'. Together they form a unique fingerprint.

  • Cite this