Abstract
We report results from the first simultaneous X-ray (RXTE) and optical (SAAO) observations of the low-mass X-ray binary GS 1826-24 in June 1998. A type-I burst was detected in both X-ray and optical wavelengths. A ~3 s optical delay with respect to the X-ray burst is observed and we infer that this is related to the X-ray reprocessing in the accretion disc. The delay provides additional support for the recently proposed orbital period of ~2 hr.