I spent the afternoon at Columbia, starting with Pizza Lunch, in which the second-year graduate students described their upcoming projects. Price-Whelan described a project with Johnston finding streams among distance-indicating stars. The three of us followed the lunch with a half-hour discussion of this. Even a single good distance-indicator in a cold stream could substantially improve our inferences about the Milky Way. It relates strongly to the fitting discussion we had with Küpper yesterday; with a good probabilistic inference framework, every new piece of data, no matter how oddly obtained, is useful. It also relates strongly to Foreman-Mackey's project to find fainter and more elusive distance indicators.
I then had a long chat with Schiminovich, which ended up with us making some plots that strongly confirm our suspicions that we can do a better job of modeling the GALEX focal plane than we have been so far. Late in the evening I submitted Lang and my mixture-of-Gaussian note to PASP. It will appear on the arXiv this week.