“The Maryanne Shelley Jessup MacConochie Colloquium” - "A New Model of Stars"

There is a lot of knowledge built in to our physical models of stars.  But there is even more information in the sum total of all the data ever taken of stars (tens of thousands of pixels of spectral data on many hundreds of thousands of targets).  The Cannon (named after Annie) uses a small amount of physical modeling and a huge amount of data to build very precise, predictive, probabilistic models of stellar spectra.  I show that these data-driven models can be used to obtain extremely precise measurements of stellar parameters and detailed chemical abundances, substantially more precise even than the physical models used to generate "ground truth" inputs.  Indeed, we believe that The Cannon working on SDSS-APOGEE data is delivering more precise chemical abundance measurements than any previous method for the analysis of stellar spectra. These results have implications for studies of exoplanets (which I won't discuss) and the Milky Way (which I will).  Work in collaboration with Melissa Ness (MPIA), Andrew R. Casey (Cambridge), Anna Y. Q. Ho (Caltech) and Hans-Walter Rix (MPIA).