Context: A radial velocity survey of about 380 G and K giant stars is ongoing
at Lick observatory. For each star we have a high signal to noise ratio
template spectrum, which we use to determine spectroscopic stellar parameters.
Aim: The aim of this paper is to present spectroscopic stellar parameters, i.e.
effective temperature, surface gravity, metallicity and rotational velocity for
our sample of G and K giant stars. Methods: Effective temperatures, surface
gravities and metallicities are determined from the equivalent width of iron
lines. Rotational velocities are determined from the full width at half maximum
(FWHM) of moderate spectral lines. A calibration between the FWHM and total
broadening (rotational velocity and macro turbulence) is obtained from stars in
common between our sample and the sample from Gray (1989). Results: The
metallicity we derive is essentially equal to the literature values, while the
effective temperature and surface gravity are slightly higher by 56 K and 0.15
dex, respectively. Our rotational velocities are comparable with the ones
obtained by Gray (1989), but somewhat higher than the ones obtained by de
Medeiros & Mayor (1999), consistent with the different diagnostics used.
Conclusions: We are able to determine spectroscopic stellar parameters for
about 380 G and K giant stars in a uniform way (112 stars are being analysed
spectroscopically for the first time). For stars available in the literature,
we find reasonable agreement between literature values and values determined in
the present work. In addition, we show that the metallicity enhancement of
companion hosting stars might also be valid for giant stars, with the
planet-hosting giants being 0.13 +/- 0.03 dex (i.e. 35 +/- 10%) more metal-rich
than our total sample of stars.Comment: 16 pages, 8 figures, 4 tables, accepted for publication by Astronomy
and Astrophysic