OPTICAL PHOTOMETRY OF SCO X-2

We present optical photometry of the galactic bulge low-mass X-ray bin ary GX 349+2 (Sco X-2) obtained in July 1993 and March 1996. Short-ter m variations up to one magnitude are present on time scales of a few h ours, which are related to the known X-ray behaviour of the source. We find (equally strong) evidence for a periodicity at either 22.3 hours or at 14.9 days. These periodicities are close to the 22 hour reporte d by Wachter Br Margon (1996) and the 14 day period reported by Southw ell et al. (1996). The two periods are related to each other through a liasing with the frequency of observations, which is approximately one day. We therefore suggest that one of the periods reported is the tru e (orbital) period, whereas the other is the similar to 1 day alias. T his confirms that both reported periods are present in the data. Indep endent of which is the real one, we conclude that the orbital period i f Sco X-2 is relatively long.