Dwarf nova

dwarf nova

Dwarf novae are a subclass of cataclysmic variables. Outbursts of dwarf novae are characterized by an amplitude of 2--8 mag, a recurrence time of a few days--10 yr, and optical spectra, in general, showing absorption lines, originated from an optically thick accretion disk. The outburst is believed to be triggered by the thermal instability of the accretion disk.