Resolved Disk Observations of Cool Mira Variables

Mira variables are among the largest stars in the menagerie of cool stars.  These 1-2 M stars exhibit dramatic year-long variations with ΔV > 3, the result of stellar pulsations that drive mass loss at 10-5 to 10-7 M/yr rates.  We have been monitoring a select set of ~100 of these stars over the past two decades with optical interferometry, Spitzer, SOFIA, and other facilities to provide unique insights into the dynamical physics and chemistry of these evolved stars. The V-band, K-band, angular size, and effective temperature variation amplitudes and periodicity have been characterized by chemical sub-type: oxygen-rich, intermediate, and carbon-rich.  Overall angular size variations are roughly 10-20%, with 150-300K excursions about 2600K average temperatures, with individual stars having up to 100 distinct epochs of size measurements.  This mix of observations is being combined into a Mira Reference Set, a laboratory to a wealth of different experiments on Miras.