Abstract

While Kepler/K2 has observed almost 400,000 stars in search of exoplanets, it has amassed a revolutionary dataset for the study of stellar magnetism. Rates of stellar flares have been determined for thousands of stars, and produced direct evidence for the evolution of flare activity with stellar age. For the first time we have been able to study the rotation rates for tens of thousands of field stars, revealing important new details about angular momentum evolution and the local star formation history. Detailed starspot properties, comparable to those measured for sunspots, have been determined for many individual stars. I will review how Kepler made each of these breakthroughs possible, and the exciting opportunities from upcoming missions such as TESS and LSST.