Stability of coorbital planets around binaries

• Published in: arXiv.org
• Main Authors: Adelbert, Stefan, Penzlin, Anna B T, Schäfer, Christoph M, Kley, Wilhelm, Quarles, Billy, Sfair, Rafael
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 11.10.2023
• Subjects: Binary stars; Configurations; Extrasolar planets; Orbital stability; Orbits; Physics - Earth and Planetary Astrophysics; Physics - Solar and Stellar Astrophysics; Planet formation; Planetary evolution; Planetary orbits
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2310.07575

In previous hydrodynamical simulations, we found a mechanism for nearly circular binary stars, like Kepler-413, to trap two planets in a stable 1:1 resonance. Therefore, the stability of coorbital configurations becomes a relevant question for planet formation around binary stars. Here, we investigate the coorbital planet stability using a Kepler-413 analogue as example and then expanding the parameters to study general n-body stability of planet pairs in eccentric horseshoe orbits around binaries. The stability is tested by evolving the planet orbits for \(10^5\) binary periods with varying initial semi-major axes and planet eccentricities. The unstable region of a single circumbinary planet is used as a comparison to the investigated coorbital configurations in this work. We confirm previous findings on the stability of single planets and find a first order linear relation between orbit eccentricity and pericentre to identify stable orbits for various binary configurations. Such a linear relation is also found for the stability of 1:1 resonant planets around binaries. Stable orbits for eccentric horseshoe configurations exist with a pericentre closer than seven binary separations and, in the case of Kepler-413, the pericentre of the first stable orbit can be approximated by \(r_{c,peri} = (2.88 e_p + 2.46) a_{bin}\).