National Optical Astronomy Observatory | 2014 Sep 03
Imagine living on an exoplanet with two suns. One, you orbit and the other is a very bright, nearby neighbor looming large in your sky. With this “second sun” in the sky, nightfall might be a rare event, perhaps only coming seasonally to your planet. A new study suggests that this could be far more common than we realized.[attachment=0]kepler-fov-wiyn.jpg[/attachment]
The NASA Kepler Space Telescope has confirmed about 1000 exoplanets, as well as thousands more stars considered “Kepler objects of interest”, dubbed KOIs – stars that could possibly host planets. Until now, there has been an unanswered question about exoplanet host stars; how many host stars are binaries? Binary stars have long been known to be commonplace – about half the stars in the sky are believed to consist of two stars orbiting each other. So, are stars with planets equally likely to have a companion star, or do companion stars affect the formation of planets? A team of astronomers, led by Dr. Elliott Horch, Southern Connecticut State University, have shown that stars with exoplanets are just as likely to have a binary companion: that is, 40% to 50% of the host stars are actually binary stars. As Dr. Horch said, “It’s interesting and exciting that exoplanet systems with stellar companions turn out to be much more common than was believed even just a few years ago.” ...
Most Sub-Arcsecond Companions of Kepler Exoplanet Candidate Host Stars are Gravitationally Bound - Elliott P. Horch et al
- arXiv.org > astro-ph > arXiv:1409.1249 > 03 Sep 2014