First thing in the morning, Andy Casey and I discussed some ideas for immediately following the first Gaia data release, which may be expanding in scope, apparently. We had the idea of gathering multi-band point-source photometry for as much of the sky as possible, and then using the data release to learn the relationship between the photometry and absolute magnitude. Then we can deliver all distances for every single point source we can! With error analysis. There would be a lot of users for such a thing.
By the end of the day, Casey had the validation working to set the regularization hyperparameter at each wavelength of the compressed-sensing version of The Cannon. Everything is looking as we predicted, so we will try to reproduce all of the results from the original Cannon paper, but now with a model with more sensible model freedom. I am extremely optimistic about where this project is going.
Mid-day I had a phone call to talk about photometry in K2 Campaign 9, which is in the bulge (and hence crowded). We discussed forward modeling and more data-driven detrending methods. But most importantly, we decided (more or less; final decision tomorrow) to do a tiny, half-pixel offset (dither) at the mid-campaign break. That might not sound like much, but I think it will significantly improve the calibration we can do and substantially increase the number of things we can learn.