TITLE: GCN CIRCULAR NUMBER: 15598 SUBJECT: GRB 131216A: Fermi-LAT detection of a burst DATE: 13/12/16 14:51:54 GMT FROM: Peter Veres at ELTE,Budapest P. Veres (Penn State), D. Kocevski (NASA/Goddard), E. Bissaldi (University & INFN Trieste), R. Desiante (University of Udine and INFN Trieste), J. Racusin (NASA/Goddard), report on behalf of the Fermi-LAT team: The Fermi Large Area Telescope (LAT) detected emission from GRB 131216A, also detected by GBM (trigger 408851795/131216081) at T0 = 01:56:32.06 UT on December 16, 2013. The GBM location was initially inside the LAT field of view at an angle of 44 degrees to the LAT boresight and triggered an autonomous repoint of the spacecraft. However, LAT did not collect data while in the South Atlantic Anomaly (SAA) from T0+200 to T0+800 s. No significant excess is seen using standard analysis procedures. Using the LAT Low Energy (LLE) event selection, over 120 counts above background were detected within a 0.3 s interval coinciding with the time of the GBM emission. This data selection has insufficient spatial resolution to provide a reliable LAT localization. Since an excess of events were not seen using the standard analysis selection, this detection is likely due to low energy gamma-rays (below 100 MeV). The Fermi LAT point of contact for this burst is Peter Veres (puv2@psu.edu). 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.