Origin of the wide-orbit circumbinary giant planet HD 106906
GALLI, P. A. B.
Institut de Planétologie et d'Astrophysique de Grenoble [IPAG]
Instituto de Astronomia, Geofísica e Ciências Atmosféricas [São Paulo] [IAG]
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Institut de Planétologie et d'Astrophysique de Grenoble [IPAG]
Instituto de Astronomia, Geofísica e Ciências Atmosféricas [São Paulo] [IAG]
Langue
en
Article de revue
Ce document a été publié dans
Astronomy and Astrophysics - A&A. 2017, vol. 602, p. A12
EDP Sciences
Résumé en anglais
Context. A giant planet has been recently resolved at a projected distance of 730 au from the tight pair of young (~13 Myr) intermediate-mass stars HD 106906AB in the Lower Centaurus Crux (LCC) group. The stars are surrounded ...Lire la suite >
Context. A giant planet has been recently resolved at a projected distance of 730 au from the tight pair of young (~13 Myr) intermediate-mass stars HD 106906AB in the Lower Centaurus Crux (LCC) group. The stars are surrounded by a debris disk which displays a ring-like morphology and strong asymmetries at multiple scales.Aims. We aim to study the likelihood of a scenario where the planet formed closer to the stars in the disk, underwent inward disk-induced migration, and got scattered away by the binary star before being stabilized by a close encounter (fly-by).Methods. We performed semi-analytical calculations and numerical simulations (Swift_HJS package) to model the interactions between the planet and the two stars. We accounted for the migration as a simple force. We studied the LCC kinematics to set constraints on the local density of stars, and therefore on the fly-by likelihood. We performed N-body simulations to determine the effects of the planet trajectories (ejection and secular effects) onto the disk morphology.Results. The combination of the migration and mean-motion resonances with the binary star (often 1:6) can eject the planet. Nonetheless, we estimate that the fly-by hypothesis decreases the scenario probability to less than 10-7 for a derived local density of stars of 0.11 stars/pc3. We show that the concomitant effect of the planet and stars trajectories induce spiral-features in the disk which may correspond to the observed asymmetries. Moreover, the present disk shape suggests that the planet is on an eccentric orbit.Conclusions. The scenario we explored is a natural hypothesis if the planet formed within a disk. Conversely, its low probability of occurrence and the fact that HD 106906 b shares some characteristics with other systems in Sco-Cen (e.g., HIP 78530, in terms of mass ratio and separation) may indicate an alternative formation pathway for those objects.< Réduire
Mots clés en anglais
Astrophysics - Earth and Planetary Astrophysics
methods: numerical
celestial mechanics
planetary systems
planets and satellites: dynamical evolution and stability
planet-disk interactions
Project ANR
Equipement d'excellence de calcul intensif de Mesocentres coordonnés - Tremplin vers le calcul petaflopique et l'exascale - ANR-10-EQPX-0029
Innovative strategies for observing and modelling natural systems - ANR-10-LABX-0056
Exploration des planetes géantes extrasolaires - ANR-14-CE33-0018
Innovative strategies for observing and modelling natural systems - ANR-10-LABX-0056
Exploration des planetes géantes extrasolaires - ANR-14-CE33-0018
Origine
Importé de halUnités de recherche