Astronomers at the International Astronomical Union meeting announced the discovery of the first transiting circumbinary multi-planet system: two planets orbiting around a pair of stars. This discovery shows that planetary systems can form and survive even in the chaotic environment around a binary star. And such planets can exist in the habitable zone of their stars.
“Each planet transits over the primary star, giving unambiguous evidence that the planets are real,” said Jerome Orosz, San Diego State University Associate Professor of Astronomy and lead author of the study which is published today in the journal Science.
This system, known as Kepler-47, contains a pair of stars that whir around each other every 7.5 days. One star is similar to the Sun while the other is a diminutive star only one third the size and 175 times fainter. The inner planet is only 3x larger in diameter than the Earth, making it the smallest known transiting circumbinary planet. It orbits the stellar pair every 49 days. LEARN MORE