Circumbinary Planet Formation in the Kepler-16 System. I. N-body Simulations

The recently discovered circumbinary planets (Kepler-16 b, Kepler 34-b, Kepler 35-b) represent the first direct evidence of the viability of planet formation in circumbinary orbits. We report on the results of N-body simulations investigating planetesimal accretion in the Kepler-16 b system, focusing on the range of impact velocities under the influence of both stars' gravitational perturbation and friction from a putative protoplanetary disk. Our results show that planet formation might be effectively inhibited for a large range in semimajor axis (1.75 <~ a_P <~ 4 AU), suggesting that the planetary core must have either migrated from outside 4 AU or formed in situ very close to its current location.