The day started with a conversation among Stuermer (Chicago), Montet (Chicago), Bedell (Flatiron), and me about the problem of deriving radial velocities from two-d spectroscopic images rather than going through one-d extractions. We tried to find scope for a minimal paper on the subject.
The day ended with a great talk by Jessi Cisewski (Yale) about topological data analysis. She finally convinced me that there is some there there. I asked about using automation to find best statistics, and she agreed that it must be possible. Afterwards, Ben Wandelt (Paris) told me he has a nearly-finished project on this very subject. Before Cisewski's talk, she spoke to Bedell and me about our EPRV plans. That conversation got me concerned about the non-identifiability of radial velocity if you let the stellar spectrum vary with time. Hmm.