1999A&A...341..487C

By chance, a Schmidt plate (+ H_α filter) was taken on 6 March 1979, 2.6 days after the famous soft gamma-ray burst that took place on 5 March. Another four plates were exposed through UVBR filters four to six days after the event. N49 - the plerionic supernova remnant presumably related to the soft gamma ray repeater - and the surrounding area have been examined, on the basis comparison with another plates taken at different epochs. No optical transient has been found within the SGR error box, nor at the position of the point X-ray source observed by ROSAT. Any variability was smaller than 0.5 mag for objects brighter than U=18, B=18, V=18 and R=20. This negative result could favour the existence of a beamed outflow that it is not aligned with the line of sight.