STIS Coronagraphic Imaging of the Herbig Ae Star: HD 163296

Abstract

Coronagraphic imaging with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope reveals a ~450 AU radius circumstellar disk around the Herbig Ae star HD 163296. A broadband (0.2-1.0 μm) reflected light image shows the disk oriented at a position angle of 140° ± 5° and inclined to our line of sight by ~60° ± 5°. The disk includes an annulus of reduced scattering at 325 AU and exhibits a flat trend of surface brightness in to 180-122 AU (15-1''), consistent with a cleared central zone. For r ≥ 370 AU the disk surface brightness drops as r to the approximately -3.5 power. The disk cannot be traced beyond 450 AU in our data. The disk is accompanied by a chain of nebulosities at P.A.=425±35, compatible with detection of a Herbig-Haro flow. The HD 163296 disk most closely resembles the disk of HD 141569. As in the HD 141569 system, the dynamical effects of a planet may be necessary to explain the structure in the outer disk.