The stability of ultra-compact planetary systems

• Published in: Astronomy and astrophysics (Berlin) 2010-06, Vol.516, p.A82
• Main Authors: Funk, B., Wuchterl, G., Schwarz, R., Pilat-Lohinger, E., Eggl, S.
• Format: Article
• Language: English
• Subjects: Astronomy; celestial mechanics; Earth, ocean, space; Exact sciences and technology; planets and satellites: general
• ISSN: 0004-6361; 1432-0746
• DOI: 10.1051/0004-6361/200912698

Aims. We investigate the dynamical stability of compact planetary systems in the CoRoT discovery space, i.e., with orbital periods of less than 50 days, including a detailed study of the stability of systems, which are spaced according to Hill's criteria. Methods. The innermost fictitious planet was placed close to the Roche limit from the star (MStar = 1 MSun) and all other fictitious planets are lined up according to Hill's criteria up to a distance of 0.26 AU, which corresponds to a 50 day period for a Sun-massed star. For the masses of the fictitious planets, we chose a range of 0.33–17 mEarth, where in each simulation all fictitious planets have the same mass. Additionally, we tested the influence of both the semi-major axis of the innermost planet and of the number of planets. In a next step we also included a gas giant in our calculations, which perturbs the inner ones and investigated their stability. Results. With numerous integrations of many different configurations we could show that long-time stable motion is possible for up to 10 planets with 17 mEarth within a distance of 0.26 AU. Further investigations show that the fictitious planets remain stable under certain circumstances even if a close-in gas giant is present.