AB Aur
AB Aur is a Herbig Ae star with a surrounding protoplanetary disk. Recently, my collaborators and I used a Monte Carlo radiative transfer code to simultaneously model the system's SED and near-IR imagery. Our results are consistent with a disk-dominated scenario, where the envelope contributes little to no observed flux. This suggests that the spirals in the system are part of the disk and might be caused by perturbations due to planetary bodies. We therefore analyzed archival data to determine if the spirals have moved over an approximately 6 year baseline. No rotation was measured. In the figure to the right, I have purposely rotated imagery of the AB Aur disk taken in 2004 and overplotted unrotated contours derived from 2009 observations of the system to place constraints on the amount of rotation that could have taken place without detection. This suggests that if gravitational interactions with planetary bodies are the origin of those spirals, the planets responsible must orbit the central star at a radius of at least 47 AU. (Lomax et al 2016)