Planet scattering around binaries: Ejections, not collisions

Rachel A. Smullen, Kaitlin Kratter, Andrew Shannon

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

Transiting circumbinary planets discovered by Kepler provide unique insight into binary star and planet formation. Several features of this new found population, for example the apparent pile-up of planets near the innermost stable orbit, may distinguish between formation theories. In this work, we determine how planet-planet scattering shapes planetary systems around binaries as compared to single stars. In particular, we look for signatures that arise due to differences in dynamical evolution in binary systems. We carry out a parameter study of N-body scattering simulations for four distinct planet populations around both binary and single stars. While binarity has little influence on the final system multiplicity or orbital distribution, the presence of a binary dramatically affects the means by which planets are lost from the system. Most circumbinary planets are lost due to ejections rather than planet-planet or planet-star collisions. The most massive planet in the system tends to control the evolution. Systems similar to the only observed multiplanet circumbinary system, Kepler-47, can arise from much more tightly packed, unstable systems. Only extreme initial conditions introduce differences in the final planet populations. Thus, we suggest that any intrinsic differences in the populations are imprinted by formation.

Original languageEnglish (US)
Pages (from-to)1288-1301
Number of pages14
JournalMonthly Notices of the Royal Astronomical Society
Volume461
Issue number2
DOIs
Publication statusPublished - Sep 11 2016

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Keywords

  • Binaries: general
  • Planet-star interactions
  • Planetary systems
  • Planets and satellites: dynamical evolution and stability

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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