On the nature of the old nova CP Puppis.

Results are reported from nearly 48 h of high-speed photometry of the ex-nova CP Pup, obtained at Sutherland or Mount Stromlo, and 23 h of spectroscopic coverage from Sutherland, during the period 1985-88. Analysis of the photometry and radial velocities derived from the spectroscopy gives a modulation period of 0.06143 d, free from the alias problems inherent in previous work, and identical for both photometry and spectroscopy. This period does not fit the data of Warner (1976) and this, together with substantial amplitude variations in the photometric modulation, suggests the presence of more than one photometric periodicity. Measurements of the radial velocity semi-amplitude give values of about 200 km/sec near the emission-line centers, decreasing to about 120 km/sec in the line wings, but with variations in phase across the line proflie.