This new paper from our UW Massive Stars research group is a first: a single-author paper from UW grad student Kathryn Neugent! This is the concluding paper of Kathryn’s PhD thesis and starts by studying the red supergiant binary fraction in the nearby galaxies M31 and M33. Kathryn then builds on that work and her previous papers to study RSG binarity as a function of metallicity with a very exciting result: she’s found clear evidence that the binary fraction of RSGs is higher at higher metallicities! This new result is both exciting and unexpected and we’re still not yet sure why the RSG binary fraction is correlated with metallicity, but we’re hoping to find out soon!

This paper has just been published in the Astrophysical Journal, and you can also check it out on arXiv!