A deeper view of the CoRoT-9 planetary system. A small non-zero eccentricity for CoRoT-9b likely generated by planet-planet scattering
Aigrain, S.;
Alonso, R.;
Bordé, P.;
Bouchy, F.;
Deleuil, M.;
Erikson, A.;
Fridlund, M.;
Moutou, C.;
Ollivier, M.;
Pätzold, M.;
Rauer, H.;
Rouan, D.;
Schneider, J.;
Gandolfi, D.;
Csizmadia, Sz.;
Cabrera, J.;
Deeg, H. J.;
Lecavelier des Etangs, A.;
Lovis, C.;
Hébrard, G.;
Bonomo, A. S.;
Díaz, R. F.;
Santerne, A.;
Guillot, T.;
Hatzes, A.;
Guenther, E.;
Almenara, J. -M.;
Damiani, C.;
Raymond, S. N.;
Izidoro, A.
Italy, France, Switzerland, United Kingdom, Spain, Germany, Argentina, Netherlands, Sweden, Brazil, United States
Abstract
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.
2017
•
Astronomy and Astrophysics
CoRoT
11
