Search for Pulsed Gamma Ray Emission above 50 MeV from NP 0532

OBSERVATIONS of the pulsar NP 0532 in the gamma ray region have yielded evidence of pulsed gamma ray emission for energies up to 10 MeV (refs. 1, 2 and Kurfess, to be published). Above this energy, upper limits between 10 MeV and 150 MeV (refs. 3, 4) and above 50 MeV (ref. 5) are indicated. A result above 70 MeV with phase error of 3 ms with respect to optical signal has been given by a counter experiment6.