Ten Low‐Mass Companions from the Keck Precision Velocity Survey

Abstract

Ten new companions have emerged from the Keck precision Doppler velocity survey, with minimum (M sin i) masses ranging from 0.8 M_JUP to 0.34 M_☉. Five of these are planet candidates with M sin i < 12 M_JUP, two are brown dwarf candidates with M sin i ~ 30 M_JUP, and three are low-mass stellar companions. Hipparcos astrometry reveals the orbital inclinations and masses for three of the (more massive) companions, and it provides upper limits to the masses for the rest. A new class of extrasolar planet is emerging, characterized by nearly circular orbits and orbital radii greater than 1 AU. The planet HD 4208b appears to be a member of this new class. The mass distribution of extrasolar planets continues to exhibit a rapid rise from 10 M_JUP toward the lowest detectable masses near 1 M_SAT.