TITLE: GCN CIRCULAR NUMBER: 22884 SUBJECT: GRB 180703B: Fermi-LAT detection DATE: 18/07/04 02:35:47 GMT FROM: Judith Racusin at GSFC J. L. Racusin (NASA/GSFC), M. Crnogorčević (UMD), A. Barker (George Washington), G. Vianello (Stanford), M. Axelsson (KTH and Stockholm University) report on behalf of the Fermi-LAT team: At 22:46:51.32 UTC on July 03, 2018 Fermi-LAT detected high-energy emission from GRB 180703B, which was also detected by Fermi-GBM (trigger 552350816 / 180703949). The best LAT on-ground location is found to be RA, Dec = 96.92, -29.88 (J2000) with an error radius of 0.4 deg (90% containment, statistical error only). This was 30 deg from the LAT boresight at the time of the trigger. The data from the Fermi-LAT show a significant increase in the event rate that is spatially and temporally correlated with the trigger with high significance. The highest-energy photon is a ~1 GeV event which is observed 35 seconds after the GBM trigger. A Swift ToO has been requested for this burst. The Fermi-LAT point of contact for this burst is Judith Racusin (judith.racusin@nasa.gov). The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.