ИСТИНА

GY Cnc is one of a few deeply eclipsing dwarf novae above the 2 − 3 hours period gap of CVs. During monitoring this long-period (P= 4.2 hours) dwarf nova photometrically, we discovered that it was undergoing an outburst in April 2014. The light curve in Rc band obtained on April10, 2014 with the 50-cm telescope in Crimea reveals that it becomes brighter on 3.5 mag. Then, 10 days later, the system declined to quiescence on April 20. During the outburst, the light curve showed a reflection effect and a possible shallow secondary eclipse around phase 0.5. Those outburst eclipse profiles are “V”-shaped and symmetric indicating an axisymmetrical brightness distribution in the accretion disc. Brightness state changes were also found during the quiescence that can be interpreted by a variable mass transfer and mass accretion. Our observations also reveal that there are three outbursts occurred in 2007, 2008, and 2009, respectively.