Origin of the wide-orbit circumbinary giant planet HD 106906

2017/03/23 by L. Rodet, H. Beust, M. Bonnefoy +5 · 41 citations
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Circumbinary planet #Galaxy #Giant planet #Orbit (dynamics) #Physics #Planet #Planetary system #Protoplanet #Protoplanetary disk #Spiral galaxy #Stars #Stellar, planetary, and galactic studies #Thick disk #astro-ph.EP

paper · pdf · doi:10.1051/0004-6361/201630269

published in Astronomy and Astrophysics 602, A12 (EDP Sciences) · 16 pages, 14 figures, 4 tables. Accepted for publication in A&A

arxiv created 2017/03/23 · openalex publication_date 2017/03/24 · arxiv updated 2017/05/24 · openalex created_date 2022/08/30 · openalex updated_date 2026/08/05

Abstract

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/pc 3 . 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.

Citations

• Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 209458
• Spiral structure when setting up pericentre glow: possible giant planets at hundreds of AU in the HD 141569 disk
• On disc driven inward migration of resonantly coupled planets with application to the system around GJ876
• Disk Frequencies and Lifetimes in Young Clusters
• THE SOUTHERN PROPER MOTION PROGRAM. IV. THE SPM4 CATALOG
• HD 106906 b: A planetary-mass companion outside a massive debris disk
• A [ITAL]Hipparcos[/ITAL] Census of the Nearby OB Associations
• A Revised Age for Upper Scorpius and The Star-Formation History Among the F-Type Members of the Scorpius-Centaurus OB Association
• Validation of the new Hipparcos reduction
• Orbital clustering of distant Kuiper belt objects by hypothetical Planet 9. Secular or resonant?
• Direct imaging of an asymmetric debris disk in the HD 106906 planetary system
• Astrometric radial velocities

Cited by

• Dynamical models to explain observations with SPHERE in planetary systems with double debris belts
• MIRI-JWST mid-infrared direct imaging of the debris disk of HD106906
• ALMA imaging of the M-dwarf Fomalhaut C’s debris disc