Brown dwarf companion with a period of 4.6 yr interacting with the hot Jupiter CoRoT-20 b

J. Rey (1) , F. Bouchy , M. Stalport , M. Deleuil (2) , G. Hébrard (3) , J.~m. Almenara , R. Alonso , S.~c.~c. Barros , A.~s. Bonomo , G. Cazalet , J.~b. Delisle , R.~f. Díaz , M. Fridlund (4) , E.~w. Guenther , T. Guillot (5) , G. Montagnier , C. Moutou , C. Lovis (1) , D. Queloz (1) , A. Santerne (2) , S. Udry (1)

1 ObsGE - Observatoire Astronomique de l'Université de Genève
2 LAM - Laboratoire d'Astrophysique de Marseille
3 IAP - Institut d'Astrophysique de Paris
4 RSSD - Research and Scientific Support Department, ESTEC
5 OCA - Observatoire de la Côte d'Azur

We report the discovery of an additional substellar companion in the CoRoT-20 system based on six years of HARPS and SOPHIE radial velocity follow-up. CoRoT-20 c has a minimum mass of 17 +/- 1 M-Jup and orbits the host star in 4.59 +/- 0.05 yr, with an orbital eccentricity of 0.60 +/- 0.03. This is the first identified system with an eccentric hot Jupiter and an eccentric massive companion. The discovery of the latter might be an indication of the migration mechanism of the hot Jupiter, via the Lidov-Kozai effect. We explore the parameter space to determine which configurations would trigger this type of interactions.

Keywords: techniques: radial velocities; stars: low-mass; stars: individual: CoRoT-20; brown dwarfs; planetary systems; planets and satellites: dynamical evolution and stability

Domains: Sciences of the Universe [physics]; Astrophysics [astro-ph]; Earth and Planetary Astrophysics [astro-ph.EP]

J. Rey, F. Bouchy, M. Stalport, M. Deleuil, G. Hébrard, et al.. Brown dwarf companion with a period of 4.6 yr interacting with the hot Jupiter CoRoT-20 b. Astronomy and Astrophysics - A&A, 2018, 619, pp.A115. ⟨10.1051/0004-6361/201833180⟩. ⟨hal-02057660⟩