The Long-Period Dwarf Nova V2466 Cyg: The 2003 and 2019 Superoutbursts

Results of the first multicolor photometric observations of the unusual dwarf nova V2466 Cygni during its 2003 and 2019 superoutbursts are presented. The total amplitude of the 2019 superoutburst in the $$R_{c}$$ band is 7.4 magnitudes. A single rebrightening was observed at the end of the 2019 superoutburst. While analyzing the $$O-C$$ diagram for the superhumps, we identified pronounced stages A, B, and C corresponding to the evolution of their period. The mean superhump period is $$P=0\overset{\textrm{d}}{.}08143(3)$$ for both superoutbursts; the superhump period derivative is $$P_{\textrm{dot}}=10.4(1.4)\times 10^{-5}$$ in stage B. We argue for the classification of V2466 Cyg as a member of a small group of objects combining the characteristics of SU UMa and WZ Sge dwarf novae and propose an explanation for the evolutionary status of these objects. As an additional result, we have discovered and studied 20 new variable stars in the neighborhoods of V2466 Cyg.