EGRET DETECTION OF HIGH-ENERGY GAMMA-RADIATION FROM THE OVV QUASAR 3C-454.3

High-energy gamma radiation has been observed from the optically violent variable (OVV) quasar 3C 454.3 (PKS 2251 + 158) by the Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Observatory. During the 1992 January-February observation, the emission showed a power-law photon spectrum with an exponent of - 2.18 +/- 0.08. The flux density (E > 100 MeV) was observed to vary within the range (0.4-1.4) x 10(-6) photon cm-2 s-1 on a time scale of less than a week. Lower sensitivity observations during 1992 April and May also detected emission within that range, but with lower statistical significance. An earlier low-sensitivity exposure during 1991 August gave a 95% confidence upper limit of 0.26 x 10(-6) photon cm-2 s-1. The similarity of the gamma-ray emission of 3C 454.3 to that of 3C 279 parallels the similarity of these two objects at lower frequencies.