Sunday, September 18, 2011
NASA's Kepler mission has announced the first direct detection of a circumbinary planet – a planet orbiting two stars- in a binary star system designated Kepler-16, located 200 light-years from Earth. While potential planets have previously been detected in other binary systems, Kepler-16b, as this newest exoplanet is now known, is the first confirmed planet to have been observed orbiting both it's parent stars.
A binary star system, as the name suggests, is a system with two stars orbiting around a common center of mass. Because from our vantage point on Earth, each of the two stars regularly passes in front of the other during their orbit, Kepler-16 is classified as an eclipsing binary.
Observations of Kepler-16 showed a drop in light from the system, not only when the stars eclipsed one another, as expected, but also a when neither star was eclipsing the other, indicating the presence of a much smaller 3rd object orbiting around them. By measuring the gravitational tug applied to the stars by this third objects, scientists were able to estimate it's mass, and Kepler-16b, as the new planet is now known, is believed to be a cold, uninhabitable world, about the size of Saturn, comprised of gas and rock.
Though Kepler-16b may be a cold, gaseous world -incapable of harboring any Jedi resistance fighters -or even sand people. As Kepler's Principal investigator William Borucki points out, the confirmation of a planet orbiting in a binary system - which are much more common than the single star system in which we reside-
"confirms a new class of planetary systems that could harbor life," and "Given that most stars in our galaxy are part of a binary system, this means the opportunities for life are much broader than if planets form only around single stars. This milestone discovery confirms a theory that scientists have had for decades but could not prove until now."
VIA: GGB on tumblr