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)