NASA scientists have found a planet with two stars about 200 light-years away from Earth. The suns are orange and red dwarfs called “binary,” located in the Kepler-16 system. It was once thought of as a George Lucas fantasy in the movie Star Wars on Luke Skywalker’s home planet.
“This is really a stunning measurement by Kepler,” said Alan Boss of the Carnegie Institution for Science, a co-author of the study. They were found by using NASA’s Kepler telescope.
The scientists say the two stars in the Kepler-16 system are orange and red dwarfs with 0.69 and 0.20 times the mass of the Sun. Their size ratio is also about 3 to 1. They eclipse each other every 41 days as they revolve around their center of mass in a mildly eccentric orbit.
When the smaller and dimmer Star B moves in front of Star A, the total light from the system fades by 13%. Kepler notes a 1.6% drop off when A blocks B.
“It’s an indication of what’s possible, something entirely new,” said Lawrence Doyle of the SETI Institute. According to Doyle’s team, this literally opens a universe of possibilities for finding Earth-like planets.
“Since half the stars in the sky you look at are binaries, this doubles the number of potential habitable planets,” said JPL Project scientist Nick Gautier.
When it comes to the planet orbiting the suns, they conclude, from the slight gravitational tugs this object exerts on the two stars, that it has only a third the mass of Jupiter. The depth of its transits shows that it has about three-fourths Jupiterâ€™s diameter. That makes it similar to Saturn but by 1.4 times more denser, suggesting that the planet is richer in heavy elements.
“We know this new planet, Kepler 16b, is about 200 light-years away and a gas giant orbiting two suns, one smaller, one larger. Life as we know it cannot exist there, but what a view it must have? You have not just the sun going across the sky, but you have it moving with another star, and they eclipse each other,” Doyle described.