... DISK т?? ... Observing . ... Star Atlas . ... Astronomy for Kids . ... Dark matter found in accretion disks . ... An artist's concept of the accretion disk around the binary star system WZ Sge. ... This material flows toward the more massive star and, in the process, forms a disk surrounding the white dwarf, known as an accretion disk. ... Stars such as WZ Sge are called cataclysmic variables due to their rapid and often large changes in brightness, all caused by variations in the accretion disk. ...