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Article Dans Une Revue Memorie della Societa astronomica italiana Année : 2006

The need for radiative levitation for understanding the properties of pulsating sdB stars.

G. Fontaine
  • Fonction : Auteur
P. Brassard
  • Fonction : Auteur
P. Chayer
  • Fonction : Auteur

Résumé

We emphasize the central role that radiative levitation plays in accounting for the very existence of the short-period pulsating EC 14026 stars as well as of the long-period PG 1716 (``Betsy'') stars. Standard models of sdB stars with uniform solar metallicity are unable to excite pulsation modes. In contrast, models which incorporate radiative levitation of iron are quite successful (especially for the EC 14026 stars) at reproducing the locations of the real pulsators in the surface gravity-effective temperature plane. In addition, radiative levitation (through its important effects on the Rosseland opacity profile) changes significantly the structure of the envelope of a sdB model, to the point where the pulsation periods are affected. We thus find that quantitative asteroseismology of pulsating sdB stars is not possible without including this key ingredient of constitutive physics.
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Dates et versions

hal-00106382 , version 1 (14-10-2006)

Identifiants

  • HAL Id : hal-00106382 , version 1

Citer

G. Fontaine, P. Brassard, S. Charpinet, P. Chayer. The need for radiative levitation for understanding the properties of pulsating sdB stars.. Memorie della Societa astronomica italiana, 2006, 77, pp.49. ⟨hal-00106382⟩
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