Photometric Long-Term Variations And Superhump Occurrence In The Classical Nova Rr Pictoris

We present an analysis of all available time-resolved photometry from the\nliterature and new light curves obtained in 2013-2014 for the old nova RR\nPictoris. The well-known hump light curve phased with the orbital period\nreveals significant variations over the last 42 years in shape, amplitude and\nother details which apparently are caused by long-term variations in the disc\nstructure. In addition we found evidence for the presence of superhumps in\n2007, with the same period (~9% longer than the orbital period), as reported\nearlier by other authors from observations in 2005. Possibly, superhumps arise\nquickly in RR Pic, but are sporadic events, because in all the other observing\nruns analysed no significant superhump signal was detected. We also determined\nan actual version of the Stolz--Schoembs relation between superhump period and\norbital period, analysing separately dwarf novae, classical novae and nova-like\nstars, and conclude that this relation is of general validity for all\nsuperhumpers among the cataclysmic variables (CVs), in spite of small but\nsignificant differences among the sub-types mentioned above. We emphasize the\nimportance of such a study in context with the still open question of the\ninterrelation between the different sub-classes of CVs, crucial for our\nunderstanding of the long-term CV evolution.\n