Impact of Stellar Dynamics on the Frequency of Giant Planets in Close Binaries

Abstract

Hostile tidal forces may inhibit the formation of Jovian planets in binaries with semimajor axes of $\la$$50\au$, binaries that might be called ``close'' in this context. As an alternative to in situ planet formation, a binary can acquire a giant planet when one of its original members is replaced in a dynamical interaction with another star that hosts a planet. Simple scaling relations for the structure and evolution of star clusters, coupled with analytic arguments regarding binary-single and binary-binary scattering, indicate that dynamical processes can deposit Jovian planets in $<$1% of close binaries. If ongoing and future exoplanet surveys measure a much larger fraction, it may be that giant planets do somehow form frequently in such systems.