Dwarf nova outbursts. II. On the nature of "narrow" and "wide" outbursts

Models with the mass transfer rate being enhanced during outbursts are calc ulated to show that (1) "narrow" outbursts correspond to the case of modera te enhancements, and (2) "wide" outbursts are most likely due to major enha ncements, which make the mass transfer rate higher than the critical dwarf nova instability level and result in steady-state accretion. Durations of s uch outburst must be controlled by factors other than the viscous time scal e of the disk.