stellar activity cycles

Ben Montet (Chicago) was visiting Flatiron today and gave a very nice talk. He gave a full review of exoplanet discovery science but focused on a few specific things. One of them was stellar activity: He has been using the NASA Kepler full-frame images (which were taken once per month, roughly) to look at precise stellar photometric variations over long timescales (because standard transit techniques filter out the long time scales, and they are hard to recover without full-frame images). He can see stellar activity cycles in many stars, and look at its relationships with things like stellar rotation periods (and hence ages) and so on. He does find relationships! The nice thing is that the NASA TESS Mission produces full-frame images every 30 minutes, so it has way more data relevant to these questions, although it doesn't observe (most of) the sky for very long. All these things are highly relevant to the things I have been thinking about for Terra Hunting Experiment and related projects, a point he made clearly in his talk.