Planets around Giant Stars

摘要

We present results from a radial-velocity survey of 373 giant stars at Lick Observatory, which started in 1999. The previously announced planets τ Drab and Pollux b are confirmed by continued monitoring. The frequency of detected planetary companions appears to increase with metallicity. The star v Oph is orbited by two brown dwarf companions with masses of 22.3 M_(Jup) and 24.5 M_(Jup) in orbits with a period ratio close to 6:1. It is likely that the two companions to v Oph formed in a disk around the star.