Confirming the Metal-Rich Nature of Stars with Giant Planets

Santos, N. C.; Israelian, G.; Mayor, M.
Bibliographical reference

The Future of Cool-Star Astrophysics: 12th Cambridge Workshop on Cool Stars , Stellar Systems, and the Sun (2001 July 30 - August 3), eds. A. Brown, G.M. Harper, and T.R. Ayres, (University of Colorado), 2003, p. 148-157.

Advertised on:
10
2003
Number of authors
3
IAC number of authors
0
Citations
6
Refereed citations
6
Description
With the goal of confirming the metallicity ``excess'' observed in stars with planetary mass companions, we have conducted a high-precision spectroscopic study of a ``comparison'' sample of dwarfs included in the CORALIE extra-solar planet survey (Santos, Israelian, & Mayor 2001). The targets were chosen following two basic criteria: they make part of a limited volume and they do not present the signature of a planetary host companion. The spectroscopic analysis, done using the very same technique as previous works on the metallicity of stars with planets, permitted a direct and non-biased comparison of the samples. The results have revealed that metallicity plays an impressive role on the giant planet formation. The chemical composition of the molecular cloud is probably the key parameter to form giant planets. Some evidences exist, however, showing the possibility of accretion of matter in the stellar outer convective zone. These conclusions impose serious constraints on the planetary systems formation and evolution models.