  The results of new spectroscopic analyses of 30 stars with giant planet
and/or brown dwarf companions are presented. Values for Teff and [Fe/H] are
used in conjunction with Hipparcos data and Padova isochrones to derive masses,
ages, and theoretical surface gravities. These new data are combined with
spectroscopic and photometric metallicity estimates of other stars harboring
planets and published samples of F, G, and K dwarfs to compare several subsets
of planet bearing stars with similarly well-constrained control groups. The
distribution of [Fe/H] values continues the trend uncovered in previous studies
in that stars hosting planetary companions have a higher mean value than
otherwise similar nearby stars. We also investigate the relationship between
stellar mass and the presence of giant planets and find statistically marginal
but suggestive evidence of a decrease in the incidence of radial velocity
companions orbiting relatively less massive stars. If confirmed with larger
samples, this would represent a critical constraint to both planetary formation
models as well as to estimates of the distribution of planetary systems in our
galaxy.

Astrophysics