2008A&A...486..505Z

We observed a new cataclysmic variable (CV) SDSS J080434.20+510349.2 to study the origin of long-term variability found in its light curve. Multi-longitude, time-resolved, photometric observations were acquired to analyze this uncommon behavior, which has been found in two newly discovered CVs. This study of SDSS J080434.20+510349.2 concerns primarily the understanding of the nature of the observed, double-humped, light curve and its relation to a cyclic brightening that occurs during quiescence. The observations were obtained early in 2007, when the object was at about V∼17.1, about 0.4mag brighter than the pre-outburst magnitude. The light curve shows a sinusoidal variability with an amplitude of about 0.07mag and a periodicity of 42.48min, which is half of the orbital period of the system. We observed in addition two ``mini-outbursts'' of the system of up to 0.6mag, which have a duration of about 4-days each. The ``mini-outburst'' has a symmetric profile and is repeated in approximately every 32-days. Subsequent monitoring of the system shows a cyclical behavior of such ``mini-outbursts'' with a similar recurrence period. The origin of the double-humped light curve and the periodic brightening is discussed in the light of the evolutionary state of SDSS J080434.20+510349.2.