modeling binaries

All hell broke loose in Heidelberg today, as Andy Casey got done with his meeting downtown, Jonathan Bird (Vanderbilt) showed up to work on the Disco proposal for the next big thing with the SDSS hardware, Ben Weiner (Arizona) showed up to talk science, and Anna Ho came in to finish her new set of papers about the LAMOST data. And even with these distractions, Price-Whelan and I “decided” (I use scare quotes because our decision was heavily influenced by Rix!) to work on the single-line binaries in the APOGEE data.

Price-Whelan and I joined up my celestial mechanics code from June with the simulated APOGEE single-visit velocities through a likelihood function and got MCMC sampling working. We showed that you can say significant things about binary stars even with only a few observations; you don't need full coverage of the orbit to make substantial statements. Though it sure helps if you want very specific orbital parameters! Tomorrow we will hit real data; we will have to put in a noise model and some outlier modeling (probably).

Bird and I discussed the high-level point of the Disco proposal: We need it to express, clearly, an idea (or set of ideas) that is worth many tens of millions of dollars. That's hard; the project is very valuable and will have huge impact per dollar, but crystallizing a complex project into one bullet point is never trivial.