Seven New Keck Planets Orbiting G and K Dwarfs

Abstract

Planetary mass companions orbiting seven nearby G and K dwarfs have been found from the Keck Precision Doppler Survey. A ‘‘ 51 Peg–like ’’ planet orbiting HD 49674 has the smallest mass yet found, Msin i ¼ 0:12 MJ. This system does not transit. A double-planet system orbits HD 37124, with periods of 153 days and 6 yr and minimum masses of 0.91 and 1.70MJ. Single companions with moderate eccentricity have been found orbiting HD 108874, HD 72659, HD 114729, and HD 145675 with orbital periods ranging from 1.09 to 5.98 yr, yielding minimum masses ranging from 0.90 to 4.87 MJ. Periodic Doppler velocity variations, consistent with a mildly eccentric planet in a 1 AU orbit, are reported for the chromospherically active K0 dwarfHD128311. It remains plausible that these velocity variations are due to stellar photospheric ‘‘ jitter.’’