Dynamical origin of S-type planets in close binary stars

Abstract

Understanding the origin of planets that have formed in binary stars is fundamental to constrain theories of binary and planet formation. The planet occurrence rate in binaries with a separation $\lesssim 50$ AU is only $\sim$ one third that of wider binaries or single stars. This may indicate that a close companion has a ruinous influence on planet formation, because it can truncate the protoplanetary disc and pump up planetesimals eccentricity and collision probability. Nevertheless, observations have revealed a few of these systems, which challenge current planet formation theories. Dynamical interactions can deliver planets into S-type orbits. In this paper, we consider as a possible scenario for forming S-type planets in close binaries the single star-binary star interactions that commonly take place in star clusters. We find that the final fraction and orbital properties of S-type planets in close binaries are mainly determined by the mass ratio of the stars involved in the close encounter, and the initial binary and planet semi-major axes. Present and upcoming missions, as TESS, PLATO and CHEOPS may shed new light on the origin of S-type planets in close binaries.

arXiv comment7 pages, 4 figures, 2 Tables, accepted by MNRAS

References in corpus (13)

• Secular Dynamics in Hierarchical Three-Body Systems
• Tidal Truncation of Inclined Circumstellar and Circumbinary Discs in Young Stellar Binaries
• The Effect of Encounters on the Eccentricity of Binaries in Clusters
• Calculating the Habitable Zone of Binary Star Systems I: S-Type Binaries
• Planet formation in Alpha Centauri A revisited: not so accretion-friendly after all
• New prospects for observing and cataloguing exoplanets in well detached binaries
• Dynamical formation & scattering of hierarchical triples: Cross sections, Kozai-Lidov oscillations, and collisions
• The Dynamical Significance of Triple Star Systems in Star Clusters
• Impact of Stellar Dynamics on the Frequency of Giant Planets in Close Binaries
• Planet Formation In Highly Inclined Binary Systems I. Planetesimals Jump Inwards And Pile Up
• Formation of S-type planets in close binaries: scattering induced tidal capture of circumbinary planets
• Transit probability of precessing circumstellar planets in binaries and exomoons
• A dynamical origin for planets in triple star systems

Cited by in corpus (4)

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• Planetary Architectures in Interacting Stellar Environments
• Encounters involving planetary systems in birth environments: the significant role of binaries
• Breaking the Mass Inclination Degeneracy of Radial Velocity Measurements via Monitoring von Zeipel-Lidov-Kozai Cycles: Implications in the HD 41004 System