A deeper view of the CoRoT-9 planetary system A small non-zero eccentricity for CoRoT-9b likely generated by planet-planet scattering

• 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 (e = 0 : 133(-0.037)(+0.042)) 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 similar to 50 M-circle plus 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.

Ämnesord

NATURVETENSKAP  -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)

Nyckelord

techniques: photometric

techniques: radial velocities

Warm

Terrestrial Planets

Sophie Velocimetry

Jupiters

Dynamical Instabilities

Hot Jupiters

Spin-Orbit Misalignments

Earth-Like Planets

planetary systems

Gas Giant Planets

Harps-N

stars: individual: CoRoT-9

Super-Earths

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)