Composite powerful flare of extremely short duration in IRAS 16293-2422

We performed detailed monitoring, over about 1 yr, of the water-vapour maser of the protostellar, nearly solar mass object, IRAS 16293. We examine a composite powerful flare of extremely short duration (∼12 d). An unusual powerful short maser flare occurred on top of a longer duration but less powerful flare, possibly initiating a powerful maser radiation of the shorter flare.

The unsaturated state of the two most powerful maser flares have been confirmed and some significant water maser parameters were obtained.