Statistical properties of exoplanets*
II. Metallicity, orbital parameters, and space velocities
Observatoire de Genève, 51 ch. des Maillettes, 1290 Sauverny, Switzerland
2 Instituto de Astrofísica de Canarias, 38200 La Laguna, Tenerife, Spain
3 Consejo Superior de Investigaciones Científicas, Spain
Corresponding author: Nuno C. Santos, Nuno.Santos@obs.unige.ch
Accepted: 7 November 2002
In this article we present a detailed spectroscopic analysis of more than 50 extra-solar planet host stars. Stellar atmospheric parameters and metallicities are derived using high resolution and high S/N spectra. The spectroscopy results, added to the previous studies, imply that we have access to a large and uniform sample of metallicities for about 80 planet hosts stars. We make use of this sample to confirm the metal-rich nature of stars with planets, and to show that the planetary frequency is rising as a function of the [Fe/H]. Furthermore, the source of this high metallicity is shown to have most probably a “primordial” source, confirming previous results. The comparison of the orbital properties (period and eccentricity) and minimum masses of the planets with the stellar properties also reveal some emerging but still not significant trends. These are discussed and some explanations are proposed. Finally, we show that the planet host stars included in the CORALIE survey have similar kinematical properties as the whole CORALIE volume-limited planet search sample. Planet hosts simply seem to occupy the metal-rich envelope of this latter population.
Key words: stars: abundances / stars: fundamental parameters / stars: chemically peculiar / stars: evolution / planetary systems / solar neighborhood
Based on observations collected at the La Silla Observatory, ESO (Chile), with the CORALIE spectrograph at the 1.2-m Euler Swiss telescope and the FEROS spectrograph at the 1.52-m ESO telescope, with the VLT/UT2 Kueyen telescope (Paranal Observatory, ESO, Chile) using the UVES spectrograph (Observing run 67.C-0206, in service mode), with the TNG and William Herschel Telescopes, both operated at the island of La Palma, and with the ELODIE spectrograph at the 1.93-m telescope at the Observatoire de Haute Provence.
© ESO, 2003