TITLE: GCN CIRCULAR NUMBER: 18419 SUBJECT: Fermi GBM trigger 466602792/151015495 is not a GRB DATE: 15/10/15 13:42:56 GMT FROM: Oliver Roberts at UCD/Fermi O.J. Roberts (UCD) reports on behalf of the Fermi GBM Team: "The Fermi Gamma-ray Burst Monitor (GBM) trigger 466602792/151015495 at 11:53:08.13 UT on 15 October 2015, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is due to particle activity."