CH Cyg is a binary star system containing a white dwarf that feeds from the wind of a red giant star. The material from the wind forms a hot accretion disk around the white dwarf before crashing onto the star. CH Cyg is one of only a few hundred symbiotic systems known, and one of the closest to the Earth. Symbiotic systems are fascinating objects, where the components are codependent and influence each other's structure, daily life, and evolution. They are likely progenitors of bipolar planetary nebulas and they could make up some of the systems that later explode as Type Ia supernovas, spectacular explosions visible across cosmological distances.
Read more at the Chandra website.