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

TL;DR

This study uses N-body simulations to explore how planets could form around binary stars like Kepler-16, revealing that planet formation is likely hindered in certain regions, implying migration or in-situ formation near current locations.

Contribution

It provides new insights into planetesimal accretion in circumbinary systems by analyzing impact velocities and gravitational effects in the Kepler-16 system.

Findings

Planet formation is inhibited between 1.75 and 4 AU.

Planetary cores likely migrated from outside 4 AU or formed close to current location.

Impact velocities influenced by binary gravitational perturbations and disk friction.

Abstract

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 semi-major 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.