Institut national de recherche scientifique français Univerité Pierre et Marie Curie Université Paris Diderot - Paris 7

An inner warp discovered in the disk around HD 110058 using VLT/SPHERE and HST/STIS

mardi 9 avril 2024, par Sophia Stasevic (LESIA)

Lundi 15 avril 2024 à 16h00 , Lieu : Salle de confĂ©rence du bâtiment 17

Dynamical interaction between debris disks and planets can induce several features in the disk, such as brightness asymmetries, warps, gaps, and spirals. Detections of such features in high-contrast imaging observations can therefore be used to infer the existence of yet-undetected companions. The edge-on debris disk detected around the young, nearby A0V star HD 110058 shows warped features resembling those seen in the disk of beta Pictoris, which could indicate the presence of a perturbing planetary-mass companion in the system. We investigated new and archival scattered light images of the disk in order to characterise its morphology and spectrum. Our work uses data from two VLT/SPHERE observations and archival data from HST/STIS. We analysed vertical profiles along the length of the disk to extract the centroid spine position and vertical height, and extracted the surface brightness and reflectance spectrum of the disk. We detect the disk between 20 au (with SPHERE) and 150 au (with STIS), at a position angle of 159.6° ± 0.6°. The disk is marginally vertically resolved in scattered light with SPHERE, with a vertical aspect ratio of 9.3 ± 0.7% at 45 au. Analysis of the spine shows an asymmetry between the two sides of the disk, with a 3.4° ± 0.9° warp between 20 au and 60 au. The outer parts of the disk are also asymmetric with a tilt between the two sides, compatible with a disk made of forward-scattering particles and an inclination of <84°. Dynamical models suggest an undetected inner planetary-mass companion on a mutually inclined orbit with the disk could explain the warp.