Polars:
Shorter timescale variability
€Light curves are strongly variable on orbital
timescales
€If accretion is occurring mainly near one magnetic pole,
then, depending on the latitude of the accretion region, this
can come into view and disappear over the limb as the
synchronised binary rotates: ³bright² and ³faint² phases
€Many systems show strong variability due to flaring on
timescales of tens of seconds
€Some systems show quasi-periodic oscillations on a timescale of seconds: this is due to an intrinsic instability in the cooling gas accreting onto the white dwarf
VV
Pup
V834
Cen
Cropper &
Warner (1986)
Larsson (1992)