Marla Geha (Yale) gave the astrophysics seminar, on the star-formation properties of low-luminosity galaxies. She (with Blanton, Tinker, Yan at NYU) finds an incredibly strong environmental effect: Low-luminosity galaxies that are far from any massive parent galaxy are all star-forming, whereas those more nearby are in a mix of star-forming and non-star-forming. It is not just a trend: There really are no non-star-forming, isolated, low-luminosity galaxies. This makes these galaxies very valuable tools for cosmlogy and galaxy formation, as Geha noted and the crowd discussed. The seminar was just what I love: Lots of constructive and interesting interruptions and discussion, mainly because the results are so interesting and valuable; this really is a significant discovery. It is the strongest (in some sense) known environmental effect for galaxies, and it immediately rules out many simplistic ideas about low-mass galaxies, like that their star formation histories will be shut off by supernova feedback.
On the airplane to visit Bloom's CTDI at Berkeley, I worked more on our side project on Lucky Imaging. I got the code working (finally) and then handed it off to Foreman-Mackey. I have to get back to the things I am supposed to be doing! (Although one of the things that I love about my job is that procrastination like this is valuable in the long term.)