Cataclysmic variable star

[1] The infalling matter, which is usually rich in hydrogen, forms in most cases an accretion disk around the white dwarf.

Strong UV and X-ray emission is often detected from the accretion disc, powered by the loss of gravitational potential energy from the infalling material.

If the accretion process continues long enough to bring the white dwarf close to the Chandrasekhar limit, the increasing interior density may ignite runaway carbon fusion and trigger a Type Ia supernova explosion, which would completely destroy the white dwarf.

Cataclysmic variables are subdivided into several smaller groups, often named after a bright prototype star characteristic of the class.

Cataclysmic variables are among the classes of astronomical objects most commonly found by amateurs, since a cataclysmic variable in its outburst phase is bright enough to be detectable with very modest instruments, and the only celestial objects easily confused with them are bright asteroids whose movement from night to night is clear.