TITLE: GCN CIRCULAR NUMBER: 11155 SUBJECT: GRB100826A: Fermi-LAT Observations DATE: 10/08/30 20:52:22 GMT FROM: Julie McEnery at NASA/GSFC Julie McEnery (NASA/GSFC) and Nicola Omodei (Stanford) report on behalf of the Fermi-LAT collaboration. The Fermi Large Area Telescope (LAT) detected emission from GRB 100826A also detected by GBM (trigger 304556304) at 22:58:22.89 on August 26, 2010. The GBM location was at a very large angle of (~70 degrees) to the LAT boresight, and no significant excess is seen using standard analysis procedures. Using a non-standard data selection, over 350 counts above background were detected within a 50 s interval coinciding with the first GBM broad peak. The LAT light curve has a very similar structure to this GBM peak, with the maximum count rate occurring at ~22 s post-trigger. A preliminary study of the instrument performance at such a large inclination suggests that these events are likely to be low energy gamma-rays, with energies less than 200 MeV. This data selection has insufficient spatial resolution to provide a reliable LAT localization. Further analysis is ongoing. The Fermi LAT point of contact for this burst is Julie McEnery (julie.mcenery@nasa.gov).