Astrophysics, abstract
astro-ph/0606121

From: Michael Endl [view email]

Date: Tue, 6 Jun 2006 15:07:37 GMT (42kb)

Exploring The Frequency Of Close-In Jovian Planets Around M Dwarfs

Authors: Michael Endl, William D. Cochran, Martin Kuerster, Diane B. Paulson, Robert A. Wittenmyer, Phillip J. MacQueen, Robert G. Tull

Comments: 20 pages (preprint), 5 figures, accepted in Astrophysical Journal

We discuss our high precision radial velocity results of a sample of 90 M dwarfs observed with the Hobby-Eberly Telescope and the Harlan J. Smith 2.7 m Telescope at McDonald Observatory, as well as the ESO VLT and the Keck I telescopes, within the context of the overall frequency of Jupiter-mass planetary companions to main sequence stars. None of the stars in our sample show variability indicative of a giant planet in a short period orbit, with a < 1 AU. We estimate an upper limit of the frequency f of close-in Jovian planets around M dwarfs as < 1.27% (at the 1 sigma confidence level). Furthermore, we determine the efficiency of our survey to have noticed planets in circular orbits as 98% for companions with m sin i > 3.8 M_Jup and a < 0.7 AU. For eccentric orbits (e=0.6) the survey completeness is 95% for all planets with m sin i > 3.5 M_Jup and a < 0.7 AU. Our results point toward a generally lower frequency of close-in Jovian planets for M dwarfs as compared to FGK-type stars. This is an important piece of information for our understanding of the process of planet formation as a function of stellar mass.

http://arxiv.org/abs/astro-ph/0606121