Kepler and K2 Timing of Active X-ray Stars

Light curve of an X-ray bright stellar pulsator, discovered by the KSwAGS survey, exhibiting a complex interplay between two fundamental periods.

Although our primary target in the Swift survey was the discovery of active galaxies, a byproduct was the discovery of a large sample of X-ray bright, active stars. Approximately half of our X-ray sources turn out to be exciting stellar objects, and include M dwarfs, rapid rotators, and delta Cepheids. The time series analysis of these objects reveal important physics in these energetic objects. For example, we will be able to track the growth, migration, and decay of starspots, as well as seeing the detailed signatures of differential rotation, activity cycles, and flaring. We have also established a large sample of late-type stars for which we can measure magnetic activity cycles, providing important constraints for developing better stellar dynamo models.