Mitchell Institute for Fundamental Physics & Astronomy
College Station, Texas 77843
The new generation of exoplanet-hunting satellites like Kepler and TESS are designed to search for the minute signals of transiting exoplanets around main sequence stars. However, many of their design properties make them ideal instruments for studying time-varying high energy systems, especially accretion disks around supermassive black holes. Such a use requires careful diagnostics and treatment due to dangerous systematics that mimic true variability, but the reward is a rich new parameter space in optical timing. I will highlight some new discoveries in AGN variability with these instruments, including a candidate quasi-periodic oscillation, characteristic variability timescales that scale with black hole mass, and possible evidence of passing obscuring clouds. I will also discuss an ongoing monitoring campaign of Fermi blazars with TESS and Swift, with possible implications for jet astrophysics, and the prospects for using exoplanet mission data for other high energy applications.