SEARCH FOR TEV GAMMA-RAYS FROM THE X-RAY PULSAR 1E2259+586

Evidence for TeV gamma-ray emission from 1E2259 + 586 has recently been reported by the Durham Group (Brazier et al. 1990). If correct, this report would be of great importance to the field of ground-based gamma-ray astronomy, as the evidence suggests that the source is a steady gamma-ray emitter, with a flux an order of magnitude higher than that of the Crab Nebula (Weekes et al. 1989). The Whipple Collaboration observed 1E2259 + 586 for a total of 80 h between November 1985 and November 1988 using the atmospheric Cherenkov imaging technique. These observations, including some taken over the same time span as the Durham observations, were analysed for evidence of periodic emission at the fundamental and second harmonic of the X-ray period. We find no evidence for gamma-ray emission from this source, and report an upper limit based on the imaging technique which is a factor of eight lower than the flux level reported by the Durham Group.