Photoelectric instability in debris disks rings: One theory to rule them all.

HST images of circumstellar debris disks have helped advance tremendously our understanding of these disks, thought to represent planetary systems during the late stages of planet formation as the gas clears and the system becomes optically thin. These systems are analogs of the Kuiper belt in the solar system, and show a variety of non-trivial structures attributed to planetary perturbations and utilized to constrain the properties of the planets. However, analyses of these systems have largely ignored the fact that, increasingly, debris disks are found to contain small quantities of gas. We have recently shown that dust-gas interactions with photoelectric heating can produce some of the key patterns seen in debris disks that were previously attributed to planets. A particularly interesting case is the disk around the star AU Microscopii, where recent HST observations show fast moving features that defy explanations. We propose to model debris disks including photoelectric heating, hydromagnetic turbulence, and radiation forces. Since AU Mic is a flare star we will include flares in our hydrodynamical models to investigate the origin of the fast moving features.