Study shows how exoplanets formed around binary stars

A new study reveals how binary stars and planets interact.

A binary star system, in which two stars are locked in orbit of each other, is one of the most hostile environments in which planets can form. The dramatic gravitational setting generated by the two stars can cause protoplanetary material to collide and shatter, preventing the formation of planets. And yet, exoplanet Kepler-34(AB)b orbits binary stars.
Now, a new study led by Stefan Lines of the University of Bristol offers an explanation as to how Kepler-34(AB)b managed to form. According to a press release, Lines and colleagues constructed a series of computer simulations to investigate the early evolution of planets orbiting binary stars; the models calculate the effects of gravity and collisions on one million pieces of protoplanetary matter.
The models revealed that Kepler-34(AB)b probably could not have formed at its current orbital distance from the binary stars. Instead, Kepler-34(AB)b and other exoplanets around binary stars would have formed in orbits much farther away from the stars, and later migrated to their current positions closer to the stars. An exception to this scenario is Kepler-47(AB)c, which is much farther from its binary stars than any other circumbinary exoplanets.
“Circumbinary planets have captured the imagination of many science-fiction writers and film-makers – our research shows just how remarkable such planets are,” Lines said. “Understanding more about where they form will assist future exoplanet discovery missions in the hunt for Earth-like planets in binary star systems.”