The X-ray cataclysmic variable 1E0643.0 −1648

We have used a new simultaneous IR/optical high-speed photometer on the UK IR telescope to study the recently discovered X-ray cataclysmic variable 1E0643.0−1648 (refs 1, 2). The light curve of this object obtained by the American Association of Variable Star Observers (AAVSO) (T. Chlebowski, personal communication) has shown it to be a dwarf nova with a recurrence time scale of 15 days. We report here that our photometry, obtained during the decline from an outburst, shows slow flickering, with the optical and IR light curves correlated with no delay. We have also obtained moderate resolution spectra of the star using the Anglo−Australian telescope.