2016/03/15 by Mark Booth, Andrés Jordán, Simón Casassus +10 · 83 citations
Physics and Astronomy · #Asteroid belt #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Debris disk #Galaxy #Giant planet #Halo #Orbit (dynamics) #Outer planets #Physics #Planet #Planetary system #Planetesimal #Stellar, planetary, and galactic studies #astro-ph.EP #astro-ph.SR
paper · pdf · doi:10.1093/mnrasl/slw040
published in Monthly Notices of the Royal Astronomical Society Letters 460(1), L10-L14 (Oxford University Press) · 5 pages, accepted by MNRAS Letters
arxiv created 2016/03/15 · openalex publication_date 2016/03/21 · arxiv updated 2016/05/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract The star HR 8799 hosts one of the largest known debris discs and at least four giant planets. Previous observations have found evidence for a warm belt within the orbits of the planets, a cold planetesimal belt beyond their orbits and a halo of small grains. With the infrared data, it is hard to distinguish the planetesimal belt emission from that of the grains in the halo. With this in mind, the system has been observed with ALMA in band 6 (1.34 mm) using a compact array format. These observations allow the inner edge of the planetesimal belt to be resolved for the first time. A radial distribution of dust grains is fitted to the data using an MCMC method. The disc is best fitted by a broad ring between 145+12-12 au and 429+37-32 au at an inclination of 40+5-6∘ and a position angle of 51+8-8∘ . A disc edge at ∼145 au is too far out to be explained simply by interactions with planet b, requiring either a more complicated dynamical history or an extra planet beyond the orbit of planet b.