Origin of the wide-orbit circumbinary giant planet HD 106906 - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Astronomy and Astrophysics - A&A Année : 2017

Origin of the wide-orbit circumbinary giant planet HD 106906

Résumé

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.
Fichier principal
Vignette du fichier
aa30269-16.pdf (2.21 Mo) Télécharger le fichier
Origine : Publication financée par une institution

Dates et versions

hal-01484948 , version 1 (16-01-2021)

Identifiants

Citer

Laetitia Rodet, H. Beust, M. Bonnefoy, A.-M. Lagrange, P. A. B. Galli, et al.. Origin of the wide-orbit circumbinary giant planet HD 106906: A dynamical scenario and its impact on the disk. Astronomy and Astrophysics - A&A, 2017, 602, pp.A12. ⟨10.1051/0004-6361/201630269⟩. ⟨hal-01484948⟩
178 Consultations
29 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More