The frequency of giant planets around metal-poor stars

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

Abstract.
The discovery of around 700 extrasolar planets, so far, has lead to the first statistics concerning extrasolar planets. The presence of giant planets seems to depend on stellar metallicity and mass. For example, they are more frequent around metal-rich stars, with an exponential increase in planet occurrence rates with metallicity. In this regard, two samples of very metal-poor stars have been analyzed to see if giant planets are indeed rare around these objects. In this unique sample, radial velocity datasets were obtained with two different spectrographs (HARPS and HIRES). Taking the detection limits for these data into account, trustworthy numbers for the planet frequency can be obtained.
The results of this study point out that giant planet frequency is indeed a strong function of metallicity. However, the frequencies are most likely higher, in the low metallicity end, than previously thought. In this talk, I will present the datasets, the methods, and most importantly, the results we have found.

Planet Formation and Evolution 2012
8th Conference on Formation and Evolution of Planetary Systems
München, Germany
setembro 2012

Tipo: Comunicação oral