Presentation #305.05 in the session Stars, Cool Dwarfs, Brown Dwarfs II.
One of the goals of the I4SAGES+ (Interferometric Imaging for Stellar and Galactic Evolution and Space Sensing) group at New Mexico Tech is to use high resolution techniques enabled by optical interferometry to understand the lives of evolved stars. Among the topics researched by the group, to which graduate and undergraduate students have had significant impacts, are mass-transfer in symbiotic star systems and surface activity and the fundamental properties of red supergiant stars. Here we highlight several of these efforts: We present new fundamental parameters of red supergiants; we use reconstructed images of RSGs and asymptotic giant branch stars (AGBs) to discuss the possible impact of surface activity on these stars on Gaia parallax uncertainties; and we present parameters of the giants in two symbiotic X-ray binary systems. We tie these varied results together with a discussion of the promise of upcoming developments in optical interferometry, including the construction of the Magdalena Ridge Observatory Interferometer, in deepening our understanding of evolved stars, particularly mass-loss processes.