Fermi LAT detection of a bright GeV gamma-ray flare from the FSRQ 3C 345

The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed high-level gamma-ray activity from a source positionally consistent with the flat spectrum radio quasar 3C 345 (also known as B2 1641+39, S4 1641+39, OS 368, 3FGL J1642.9+3950), with VLBI coordinates (J2000.0), R.A. 250.745041 deg, Dec. 39.810276 deg (Johnston et al. 1995, AJ, 110, 880).