  We describe some of the recent observations of Dwarf Nova Oscillations and
Quasi-Periodic Oscillations in cataclysmic variable stars. The similarities to
high frequency QPOs seen in X-Ray binaries make this an increasingly useful
field to explore. Our principal new result is the discovery of 1:2:3 harmonic
structure in the DNOs of VW Hyi late in outburst. Similar structure is seen in
the QPOs of some black hole and neutron star X-Ray binaries. In VW Hyi there is
a sudden frequency-doubling when the DNO period reaches ~39 s. This first
harmonic increases in period to ~28 s at which point the second harmonic
appears. Both harmonics continue with increasing period, together or
separately, with an occasional appearance of the fundamental, until the latter
reaches ~105 s, by which time VW Hyi has fallen to its quiescent magnitude. We
also report the first extensive observations of DNOs in a dwarf nova (OY Car)
in quiescence. These are lpDNOs (longer period DNOs) and show similar short
time scale properties to the DNOs and lpDNOs seen in outburst.

Astrophysics