Chemical abundances of 22 extrasolar planet host stars

Abstract

We present observations of 22 extrasolar planet host stars and derive their stellar parameters. With the high signal-to-noise ratio spectra, we acquire accurate metallicities and the differential abundances for 15 other elements and we discuss the relation between the abundance ratio and the metallicity. These sample stars are metal-rich relative to the Sun, covering the range from -0.04 to 0.54 dex with the average [Fe/H] value of 0.15 ± 0.12 dex, except for HD 37124, which has [Fe/H] = -0.45. The stars with planets show a slight overabundance pattern for [C/Fe] and [Mg/Fe], but [Na/Fe], [Al/Fe], [Si/Fe], [Ti/Fe], [Cr/Fe], [Sc/Fe], [V/Fe], [Ni/Fe] and [Ba/Fe] are approximately solar in the sample stars. These stars also show slight underabundances for [O/Fe], [Ca/Fe] and [Mn/Fe]. The sulphur displays enhanced values, ranging from -0.10 to 0.40 through the sample stars. These results are used to investigate the connection between giant planets and high metallicity and to probe the influence of the process on the other elements. © 2005 RAS.