The frequency of planets around metal-poor stars

A. Mortier, N. C. Santos, A. Sozzetti, D. W. Latham, M. Mayor, S. Udry

Abstract.
Since the detection of the first exoplanet in 1995, hundreds of exoplanets have been announced. Statistics can be made with this growing sample of exoplanets. It has been shown that stellar mass and metallicity seem to play a role in the formation process of a planet. Understanding the frequency of different types of planets around stars of different mass and metallicity is thus providing clues about the processes of planet formation and evolution.
Different samples of stars were created to search for planets with this goal in mind. Two of these samples were observed with the HARPS and Keck-HIRES spectrographs, respectively. They are samples of metal-poor solar-type stars. This combined sample provides a tool to determine the detection limits to find planets orbiting these metal-poor stars. That way the metallicity limit under which no (giant) planet can be observed anymore can be determined.
In this talk, we will present the first results of the statistics of this combined sample.

XXI Encontro Nacional de Astronomia e Astrofisica
Coimbra, Portugal
September 2011

Type: Oral comunication