Is there a metallicity enhancement in planet hosting red giants?

Zieliński, Pawel
Niedzielski, Andrzej
Adamów, Monika
Wolszczan, Aleksander
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The Penn State/Toru\'n Centre for Astronomy Search for Planets Around Evolved Stars is a high-precision radial velocity (RV) survey aiming at planets detection around giant stars. It is based on observations obtained with the 9.2 m Hobby-Eberly Telescope. As proper interpretation of high precision RV data for red giants requires complete spectral analysis of targets we perform spectral modeling of all stars included in the survey. Typically, rotation velocities and metallicities are determined in addition to stellar luminosities and temperatures what allows us to estimate stellar ages and masses. Here we present preliminary results of metallicity studies in our sample. We search a metallicity dependence similar to that for dwarfs by comparing our results for a sample of 22 giants earlier than K5 showing significant RV variations with a control sample of 58 relatively RV-stable stars.
Comment: 5 pages, 2 figures. To appear in "Extrasolar Planets in Multi-body Systems: Theory and Observations"
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Earth and Planetary Astrophysics