Using Spitzer Space Telescope observations of the interacting binary WZ Sge, we have discovered that the accretion disk is far more complex than previously thought. Our IRAC channel 2 and 4 time series observations reveal that the size of the accretion disk is far greater then currently believed and modeled (based on optical and UV observations) over the past few decades. Our preliminary findings suggest that the accretion disk contains a large, cool outer dust ring likely to extend to far greater radius than currently believed.
These observations have great relevance for accretion disks in general, those in binary systems as well as in active galaxies. This new Spitzer/NOAO Research Program for Teachers and Students proposal will provide observations of the eclipsing dwarf nova Z Cha that will test and confirm our new findings, as well as provide the basis for additional classroom and EPO activities related to infrared astronomy, eclipsing binary stars, and the process of mass transfer/accretion.