A team of astronomers from NASA and San Diego State University have discovered a distant planet that orbits two starts like the fictional Tatooine in Star Wars.
The planet Kepler-1647 b, found using the Kepler Space Telescope, orbits two stars in the constellation Cygnus some 3,700 light years from Earth. It is the largest “circumbinary” planet discovered to date.
The discovery was announced Monday in San Diego, at a meeting of the American Astronomical Society.
Using the Kepler telescope, astronomers searched for slight dips in brightness that hint a planet might be transiting in front of the stars, blocking some of the stars’ light.
“Finding circumbinary planets is much harder than finding planets around single stars,” said SDSU astronomer William Welsh, a member of the team. “The transits are not regularly spaced in time and they can vary in duration and even depth.”
Laurance Doyle, an astronomer at the SETI Institute, noticed a transit back in 2011. But more data and several years of analysis were needed to confirm the transit was indeed caused by a circumbinary planet.
The two stars are similar to the Sun, with one slightly larger than our home star and the other slightly smaller. The planet has a mass and radius nearly identical to that of Jupiter.
The planet takes 1,107 days to orbit its host stars, and lies within the so-called habitable zone. But like Jupiter, Kepler-1647 b is a gas giant unlikely to itself host life, though it could have large moons that are hospitable.
