Gravitational Microlensing Evidence for a Planet Orbiting a Binary Star System
Abstract
The study of extra-solar planetary systems has emerged as a new discipline of observational astronomy in the past few years with the discovery of a number of extra-solar planets. The properties of most of these extra-solar planets were not anticipated by theoretical work on the formation of planetary systems. Here we report observations and light curve modeling of gravitational microlensing event MACHO-97-BLG-41, which indicates that the lens system consists of a planet orbiting a binary star system. According to this model, the mass ratio of the binary star system is 3.8:1 and the stars are most likely to be a late K dwarf and an M dwarf with a separation of about 1.8 AU. A planet of about 3 Jupiter masses orbits this system at a distance of about 7 AU. If our interpretation of this light curve is correct, it represents the first discovery of a planet orbiting a binary star system and the first detection of a Jovian planet via the gravitational microlensing technique. It suggests that giant planets may be common in short period binary star systems.
Cite
@article{arxiv.astro-ph/9908038,
title = {Gravitational Microlensing Evidence for a Planet Orbiting a Binary Star System},
author = {D. P. Bennett and S. H. Rhie and A. C. Becker and N. Butler and J. Dann and S. Kaspi and E. M. Leibowitz and Y. Lipkin and D. Maoz and H. Mendelson and B. A. Peterson and J. Quinn and O. Shemmer and S. Thomson and S. E. Turner},
journal= {arXiv preprint arXiv:astro-ph/9908038},
year = {2009}
}
Comments
11 pages, with 1 color and 2 b/w Figures included (published version)