A deeper view of the CoRoT-9 planetary system

Journal article

CoRoT-9b is one of the rare long-period (P = 95.3 days) transiting giant planets with a measured mass known to date. We present a new analysis of the CoRoT-9 system based on five years of radial-velocity (RV) monitoring with HARPS and three new space-based transits observed with CoRoT and Spitzer. Combining our new data with already published measurements we redetermine the CoRoT-9 system parameters and find good agreement with the published values. We uncover a higher significance for the small but non-zero eccentricity of CoRoT-9b () and find no evidence for additional planets in the system. We use simulations of planet-planet scattering to show that the eccentricity of CoRoT-9b may have been generated by an instability in which a ∼ 50 M ⊕ planet was ejected from the system. This scattering would not have produced a spin-orbit misalignment, so we predict that the CoRoT-9b orbit should lie within a few degrees of the initial plane of the protoplanetary disk. As a consequence, any significant stellar obliquity would indicate that the disk was primordially tilted.

Authors: Bonomo, AS; Hébrard, G; Raymond, SN; Bouchy, F; Etangs, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: EDP Sciences
• Journal: Astronomy and Astrophysics
• Volume: 603
• Article number: A43
• Publication date: 2017-07-05
• Acceptance date: 2017-03-15
• DOI: 10.1051/0004-6361/201730624
• EISSN: 1432-0746
• ISSN: 0004-6361
• Language: English
• Keywords: techniques: photometric; planetary systems; stars: individual: CoRoT-9; techniques: radial velocities