Gravity-mode pulsations in subdwarf B stars: A critical test of stellar opacity

C. S. Jeffery, H. Saio

Research output: Contribution to journalLetterpeer-review

59 Citations (Scopus)


The identification of non-radial g-mode oscillations as the cause of variability in cool subdwarf B stars (PG 1716 variables) has been frustrated by a 5000-K discrepancy between the observed and theoretical blue-edge of the instability domain. A major component in the solution to this problem has been identified by (i) using updated Opacity Project (OP) instead of OPAL opacities and (ii) considering an enhancement of nickel, in addition to that of iron, in the driving zone. The reason for this success is that, in OP, the 'Fe-bump' contributions from iron and nickel occur at higher temperatures than in OPAL. As well as pointing to a solution of an important problem in stellar pulsation theory, this result provides a critical test for stellar opacities and the atomic physics used to compute them.

Original languageEnglish
Pages (from-to)L48-L52
JournalMonthly Notices of the Royal Astronomical Society: Letters
Issue number1
Publication statusPublished - 2006 Oct
Externally publishedYes


  • Atomic processes
  • Radiative transfer
  • Stars: early-type
  • Stars: horizontal branch
  • Stars: interiors
  • Stars: oscillations

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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