Asteroseismology of exoplanets hosts stars: Tests of internal metallicity

M. Bazot, S. Vauclair

Research output: Contribution to journalArticle

Abstract

Exoplanet host stars present a clear metallicity excess compared to stars without detected planets, with an average overabundance of 0.2 dex. This excess may be primordial, in which case the stars should be overmetallic down to their center, or it may be due to accretion in the early phases of planetary formation, in which case the stars would be overmetallic only in their outer layers. In the present paper, we show the differences in the internal structure of stars, according to the chosen scenario. Namely two stars with the same observable parameters (luminosity, effective temperature, outer chemical composition) are completely different in their interiors according to their past histories, which we reconstitute through the computations of their evolutionary tracks. It may happen that stars with an initial overmetallicity have a convective core while the stars which suffered accretion do not. We claim that asteroseismic studies of these exoplanet host stars can give clues about their internal structures and metallicities, which may help in understanding planetary formation.

Original languageEnglish (US)
Pages (from-to)965-973
Number of pages9
JournalAstronomy and Astrophysics
Volume427
Issue number3
DOIs
StatePublished - Dec 1 2004

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Keywords

  • Abundances - Stars
  • Formation - Stars
  • Oscillations
  • Planetary systems
  • Stars

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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