Seven New Keck Planets Orbiting G and K Dwarfs

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, Msini=0.12 M<sub>J</sub>. 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 1.70 M<sub>J</sub>. 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 M<sub>J</sub>. Periodic Doppler velocity variations, consistent with a mildly eccentric planet in a 1 AU orbit, are reported for the chromospherically active K0 dwarf HD 128311. It remains plausible that these velocity variations are due to stellar photospheric ``jitter.'' Based on observations obtained at the W. M. Keck Observatory, which is operated jointly by the University of California and the California Institute of Technology. Keck time has been granted by both NASA and the University of California.