Insights into the planetary dynamics of HD 206893 with ALMA - Archive ouverte HAL Access content directly
Journal Articles Monthly Notices of the Royal Astronomical Society Year : 2020

Insights into the planetary dynamics of HD 206893 with ALMA

, , , (1) , , , , , (1) , ,
1
S. Marino
  • Function : Author
A. Zurlo
  • Function : Author
V. Faramaz
  • Function : Author
Th Henning
  • Function : Author
G. M. Kennedy
  • Function : Author
L. Matrà
  • Function : Author
S. Pérez
  • Function : Author
L. A. Cieza
  • Function : Author
A. M. Hughes
  • Function : Author

Abstract

Radial substructure in the form of rings and gaps has been shown to be ubiquitous among protoplanetary discs. This could be the case in exo-Kuiper belts as well, and evidence for this is emerging. In this paper, we present ALMA observations of the debris/planetesimal disc surrounding HD 206893, a system that also hosts two massive companions at 2 and 11 au. Our observations reveal a disc extending from 30 to 180 au, split by a 27 au wide gap centred at 74 au, and no dust surrounding the reddened brown dwarf (BD) at 11 au. The gap width suggests the presence of a 0.9MJup planet at 74 au, which would be the third companion in this system. Using previous astrometry of the BD, combined with our derived disc orientation as a prior, we were able to better constrain its orbit finding it is likely eccentric ($0.14^{+0.05}_{-0.04}$). For the innermost companion, we used radial velocity, proper motion anomaly, and stability considerations to show its mass and semimajor axis are likely in the ranges 4-100MJup and 1.4-4.5 au. These three companions will interact on secular time-scales and perturb the orbits of planetesimals, stirring the disc and potentially truncating it to its current extent via secular resonances. Finally, the presence of a gap in this system adds to the growing evidence that gaps could be common in wide exo-Kuiper belts. Out of six wide debris discs observed with ALMA with enough resolution, four to five show radial substructure in the form of gaps.
Fichier principal
Vignette du fichier
staa2386.pdf (3.36 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

insu-03705173 , version 1 (27-06-2022)

Licence

Attribution - CC BY 4.0

Identifiers

Cite

S. Marino, A. Zurlo, V. Faramaz, J. Milli, Th Henning, et al.. Insights into the planetary dynamics of HD 206893 with ALMA. Monthly Notices of the Royal Astronomical Society, 2020, 498, pp.1319-1334. ⟨10.1093/mnras/staa2386⟩. ⟨insu-03705173⟩
19 View
3 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More