I spent the day at Ohio State University today, visiting the Physics and Astronomy Departments. I had a great time! Too many things happened to mention them all, but here are some highlights:
At the arXiv coffee discussion, among other results we discussed was a new paper by Radek Poleski and colleagues in which they identify hundreds of thousands of variable stars in the OGLE data set. Poleski showed some examples, which included eclipsing binaries in which both stars are elongated tidally (and it is obvious in the light curves), transiting exoplanets, transiting exoplanets where the transits come and go like there is rapid precession, periodic variables, periodic variables with second derivatives in the period (hence possibly accelerations) and so on. He claims that every single one of the variables was checked by hand.
In the stars group meeting run by Jennifer Johnson, we discussed mainly stellar rotation, and how it connects to age and stellar evolution. Johnson runs the group meeting such that each participant brings a figure (if they can) and that figure is discussed and improved. That's a good idea. Also in that meeting we discussed what to do if your result is scooped!
In the galaxies group meeting towards the end of the day, we argued about the dimensionality of chemical-abundance space, both in theory and in the observations, with me arguing that obviously the observational space is higher dimensionality than any theory space. But David Weinberg challenged me, and forced me to sharpen my arguments, and also make better plans for whatever paper I am going to write about this!