I have searched for some literatures and found following historical outbursts of QY Per. from Veroeff. Sternwarte Sonneberg 9, 125 (1979) JD mag 2438642 <17.0 51 14.2 52 14.15 53 14.7 69 <17.0 2440484 16.8: 500 16.0 501 16.5: 504 16.1: 511 16.1: The authors (H. Busch & K. Haeussler) states that the cycle length is about 370 days (probably concluded from other outburst observations not listed in their table). from IAUC No. 4900 (Rosino) mag ~ 14.9 on 1989 Oct. 30 & 31. Regards, Taichi Kato