detailed abundance trends with binarity

Taisiya Kopytova (ASU) arrived in New York today for two days to work on the detailed chemical abundances of giant stars in APOGEE that host substellar and low-mass stellar companions. We have cast this problem as a very simple comparison between the companion-hosting population and a control sample. The control sample is carefully selected to be identical in stellar parameters. It looks like she has a result, and the result is interesting. It isn't a large effect, however. We discussed how to show it, convincingly, and how to describe it, accurately.

Lauren Anderson (Flatiron) and I continued to debate how to put spectroscopic labels onto Gaia TGAS stars without spectroscopy, and how to (before that) de-noise the labels themselves, which we are getting from the RAVE-on catalog of Andy Casey et al. We are a bit confused about how principled to be in the latter de-noising. It seems crazy to proceed without doing it, but building a full hierarchical model seems like overkill when the main point is just that stars on the main-sequence must have large surface gravities!

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