It was a great day at CampHogg today! Foreman-Mackey defended his PhD thesis with a great talk. Although his thesis also contained chapters about MCMC sampling, exoplanet populations, and finding isolated transit events in lightcurves, he concentrated his oral presentation on the discovery of periodic transits in the K2 data. This permitted him to touch on many aspects of his work, including especially the marginalization out of systematics (instrument-induced signals). He made a very strong case that we need to fit the systematics simultaneously with the signals of interest, because in any other approach (any pre-filtering or data conditioning method), you end up either very strongly restricting the systematics model (so it doesn't do what you need) or else you end up over-fitting and distorting your transit signals. The thesis talk was followed by extensive questioning and the signing of forms.
As my loyal reader can infer from what's written in the many posts on this blog, Foreman-Mackey has had a huge impact on every aspect of my scientific life. I have learned far more from him than he has learned from me. He has achieved a lot, in tool building and in the production of valuable scientific results. I still get a few more weeks of Foreman-Mackey but then he is off to Seattle to start his Sagan Fellowship.