Substructure in the Circumstellar Disk around the Young Star AU Mic (GJ 803)

Abstract

Keck adaptive optics imaging with a physical resolution of 0.4 AU resolves the inner (15-80 AU) disk of AU Mic (GJ 803), the nearest known scattered light disk to Earth. The inner disk is asymmetric and possesses a sharp change in structure at 35 AU. The disk also shows spatially localized enhancements and deficits at 25-40 AU separations. The overall morphology points to the influence of unseen larger bodies and resembles structures expected from recent planet formation. AU Mic is coeval with the archetypical debris disk system beta Pic, and the similarities between their two disks point to synchronous disk evolution. Multiple indications of substructure appear to be common in circumstellar disks at an age of ~12 Myr.