Rotating convective core excites non-radial pulsations to cause rotational modulations in early-type stars

Umin Lee, Hideyuki Saio

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

We discuss low-frequency g modes excited by resonant couplings with weakly unstable oscillatory convective modes in the rotating convective core in early-type main-sequence stars. Our non-adiabatic pulsation analyses including the effect of Coriolis force for 2\, \mathrm{ M⊙ main-sequence models show that if the convective core rotates slightly faster than the surrounding radiative layers, g modes in the radiative envelope are excited by a resonance coupling. The frequency of the excited g mode in the inertial frame is close to -mωc- with m and ωc being the azimuthal order of the g mode and the rotation frequency of the convective core, respectively. These g-mode frequencies are consistent with those of photometric rotational modulations and harmonics observed in many early-type main-sequence stars. In other words, these g modes provide a non-magnetic explanation for the rotational light modulations detected in many early-type main-sequence stars.

Original languageEnglish
Pages (from-to)4117-4127
Number of pages11
JournalMonthly Notices of the Royal Astronomical Society
Volume497
Issue number4
DOIs
Publication statusPublished - 2020 Oct 1
Externally publishedYes

Keywords

  • stars: early-type
  • stars: oscillations
  • stars: rotation

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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