An Outburst by AM CVn Binary SDSS J113732.32+405458.3

Abstract We report the discovery of a one magnitude increase in optical brightness 59.63 minutes orbital period AM CVn binary SDSS J113732.32+405458.3. Public g , r and i band data from Zwicky Transient Facility exhibit subsequent decline over 300 days period, while few points commissioning show that peak was likely seen. Such an outburst is due to change state accretion disk, making this longest reveal unstable disk. The object now back its previously observed (by PS-1) quiescent set by accreting white dwarf. Prior observations also imply recurrence times for such outbursts are more than 12 yr.