The long term optical behaviour of helium accreting AM CVn binaries
  We present the results of a two and a half year optical photometric
monitoring programme covering 16 AM CVn binaries using the Liverpool Telescope
on La Palma. We detected outbursts in seven systems, one of which (SDSS J0129)
was seen in outburst for the first time. Our study coupled with existing data
shows that ~1/3 of these helium-rich accreting compact binaries show outbursts.
The orbital period of the outbursting systems lie in the range 24-44 mins and
is remarkably consistent with disk-instability predictions. The characteristics
of the outbursts seem to be broadly correlated with their orbital period (and
hence mass transfer rate). Systems which have short periods (<30 min) tend to
exhibit outbursts lasting 1--2 weeks and often show a distinct `dip' in flux
shortly after the on-set of the burst. We explore the nature of these dips
which are also seen in the near-UV. The longer period bursters show higher
amplitude events (5 mag) that can last several months. We have made simulations
to estimate how many outbursts we are likely to have missed.
