LCs of 9 rapidly evolving transients

The search yielded 19 bona fide RET candidates, corresponding to a discovery rate of ~5.2 events per year. Even with a Galactic latitude cut of 20{deg}, eight of the 19 events (~42%) are Galactic, including one with a light-curve shape closely resembling that of the GW170817 kilonova (KN).

An additional event is a nova in M31. Four out of the 19 events (~21%) are confirmed extragalactic RETs (one confirmed here for the first time) and the origin of six additional events cannot be determined. We did not find any extragalactic events resembling the GW170817 KN, from which we obtain an upper limit on the volumetric rate of GW170817-like KNe of R<=2400Gpc^-3^/yr (95% confidence).