%0 Journal Article
%T A Planetary Companion to the Nearby M4 Dwarf, Gliese 876
%A G. W. Marcy
%A R. P. Butler
%A S. S. Vogt
%A D. A. Fischer
%A J. J. Lissauer
%J Physics
%D 1998
%I arXiv
%R 10.1086/311623
%X Doppler measurements of the M4 dwarf star, Gliese 876, taken at both Lick and Keck Observatory reveal periodic, Keplerian velocity variations with a period of 61 days. The orbital fit implies that the companion has a mass of, M = 2.1 MJUP /sin i, an orbital eccentricity of, e = 0.27+-0.03, and a semimajor axis of, a = 0.21 AU. The planet is the first found around an M dwarf, and was drawn from a survey of 24 such stars at Lick Observatory. It is the closest extrasolar planet yet found, providing opportunities for follow--up detection. The presence of a giant planet on a non-circular orbit, 0.2 AU from a 1/3 M_Sun star, presents a challenge to planet formation theory. This planet detection around an M dwarf suggests that giant planets are numerous in the Galaxy.
%U http://arxiv.org/abs/astro-ph/9807307v1