Santos, Nuno

Contact Email: nuno.santos@obs.unige.ch
Institute: Geneva Observatory
First Coauthor: Michel Mayor
Institute: Geneva Observatory
Second Coauthor: Garik Israelian
Institute: Instituto de Astrofisica de Canarias
Research URL:http://obswww.unige.ch/~udry/planet/planet.html
Presenting Thesis: Yes
Subject Area: Brown Dwarfs & Extrasolar Planets
Waveband: Optical
Technique: Spectroscopy
Presentation: Oral Contribution: Tuesday
Title: Confirming the metal-rich nature of stars with giant planets
Abstract: 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. 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 was done using the very same technique as previous works on the metallicity of stars with planets, permitting a direct and non-biased comparison of the samples. The results show that stars with planets are significantly metal rich. Furthermore, they point out towards a ``primordial'' source for the high abundances. This latter result implies that the chemical composition of the molecular cloud is the key parameter to form giant planets. These conclusions may thus impose serious constraints on the planetary systems formation and evolution models.