Photometric study of selected cataclysmic variables
  We present time-resolved photometry of five relatively poorly-studied cataclysmic variables: V1193 Ori, LQ Peg, LD 317, V795 Her, and MCT 2347-3144. The observations were made using four 1m-class telescopes for a total of more than 250 h of observation and almost 16,000 data points. For LQ Peg WHT spectroscopic data have been analysed as well.   The light curves show a wide range of variability on different time scales from minutes to months. We detect for the first time a brightness variation of 0.05 mag in amplitude in V1193 Ori on the same timescale as the orbital period, which we interpret as the result of the irradiation of the secondary. A 20-min quasi-periodic oscillation is also detected. The mean brightness of the system has changed by 0.5 mag on a three-month interval, while the flickering was halved. In LQ Peg a 0.05 mag modulation was revealed with a period of about 3 h. The flickering was much smaller, of the order of 0.025 mag. A possible quasi-periodic oscillation could exist near 30 min. For this object, the WHT spectra are single-peaked and do not show any radial-velocity variations. The data of LD 317 show a decrease in the mean magnitude of the system. No periodic signal was detected but this is certainly attributable to the very large flickering observed: between 0.07 and 0.1 mag. For V795 Her, the 2.8-hour modulation, thought to be a superhump arising from the precession of the disc, is present. We show that this modulation is not stable in terms of periodicity, amplitude, and phase. Finally, for MCT 2347-3144, a clear modulation is seen in a first dataset obtained in October 2002. This modulation is absent in August 2003, when the system was brighter and showed much more flickering. 
C. Papadaki, H.M.J. Boffin, C. Sterken, V. Stanishev, J. Cuypers, P.   Boumis, S. Akras and J. Alikakos