Rapid oscillations in cataclysmic variables

I give an overview of the rich phenomenology of dwarf nova oscillations (DNOs) and quasi-periodic oscillations (QPOs) observed in cataclysmic variable stars (CVs). The favored interpretation of these rapid brightness modulations (3 to >1000 s timescales) is that they are magnetic in nature - magnetically channeled accretion from the inner accretion disk for DNOs and possible magnetically excited traveling waves in the disk for QPOs. There is increasing evidence for the magnetic aspects, which extend to lower fields the well-known properties of strong field (polar) and intermediate strength field (intermediate polar) CVs. The result is that almost all CVs show the presence of magnetic fields on their white dwarf primaries, although for many the intrinsic field may be locally enhanced by the accretion process itself. There are many behaviors that parallel the QPOs seen in X-ray binaries, with high- and low-frequency X-ray QPOs resembling, respectively, the DNOs and QPOs in CVs.