The Lick Planet Search: Detectability and Mass Thresholds

We present an analysis of 11 yr of precision radial velocity measurements of 76 nearby solar-type stars from the Lick radial velocity survey. For each star, we report on variability, periodicity, and long-term velocity trends. Our sample of stars contains eight known companions with mass less than 8 (M p sin i) Jupiter masses six of which were discovered at Lick. For the remaining stars, we place upper limits (M J ), on the companion mass as a function of orbital period. For most stars, we can exclude companions with velocity amplitude m s~1 at the 99% level, or for orbital radii KZ 20 M p sin i Z 0.7M J (a/AU)1@2 a [ 5 AU. We examine the implications of our results for the observed distribution of mass and orbital radius of companions. We show that the combination of intrinsic stellar variability and measurement errors most likely explains why all conrmed companions so far have m s~1. The nite duration of the KZ 40 observations limits detection of Jupiter-mass companions to A...