Published online by Cambridge University Press: 12 April 2016
We present a model for the dwarf nova WZ Sge which does not imply an unusually – and unexplained – low value of the viscosity during low states. We propose that the inner parts of the accretion disc are disrupted by either a magnetic field or evaporation, so that the disc is stable (or very close to being stable) in quiescence, as the mass transfer rate is very low, and the disc can sit on the cool, lower branch of the thermal equilibrium curve. Outbursts are triggered by an increase of mass transfer, causing a standard disc instability, and are strongly enhanced by illumination effects. Both the recurrence time, and the characteristics of the light curve in outburst can be accounted for.