Rapid variations in Cataclysmic Variable Stars

An overview will be given of high speed brightness variations and their interpretation in novae, dwarf novae and nova-like variable stars, all of which are close binaries containing white dwarf stars. These variations take place on time scales of seconds to hundreds of seconds, are often visible while one is observing, and draw on a variety of physical mechanisms for their understanding. Quasi-periodic variations are attributed to magnetically-controlled accretion from the inner edge of an accretion disc, and are seen in X-Ray binaries containing neutron stars and black holes. Multi-periodic stable variations arise from non-radial oscillations of the white dwarf component of the binary, and give the potential of showing the internal structure of accreting white dwarfs.