Cataclysmic variable binary star system. Image 1 of 2. Artwork of the low state of this binary star system. A red dwarf star (upper left) is in mutual orbit with a white dwarf star (lower right) that has an accretion disc (red) forming around it. This disc forms as the gravity of the white dwarf star pulls material from the red dwarf star. In this low state, the flow of material between the stars is low, allowing it to slowly accumulate on the white dwarf star. When the rate of flow is higher, the system can enter a high state (seen in image R670/176) preceding a nova (large increase in brightness). A white dwarf star is a collapsed star with an intense gravitational field.