Superhumps in cataclysmic binaries. XIII. CP Puppis

We report new photometry of the old nova CP Puppis and Study timing effects in the photometric waves seen during 1985-1998. A possibly stable signal is present at a period consistent with 0.06143(3) days, which is the orbital period deduced From spectroscopy. In addition, there is a transient signal at a slightly longer period. Measurement of the latter signal on individual nights, free from aliasing, yields P = 0.0627(6) days, and measurement over longer baselines yields a mean value of P = 0.0625(2) days. The properties of this signal (instability in period and amplitude, and period excess of 2% over P-orb) are the usual signatures of "superhumps" in cataclysmic variables.