TITLE: GCN CIRCULAR NUMBER: 21880 SUBJECT: Fermi GBM trigger 526978609/170913289 is not a GRB DATE: 17/09/13 08:38:52 GMT FROM: Andreas von Kienlin at MPE A. von Kienlin (MPE) reports on behalf of the Fermi Gamma-ray Burst Monitor Team: “The Fermi Gamma-ray Burst Monitor (GBM) trigger 526978609/170913289 at 06:56:44.85 UT on 13 September 2017, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is due to local particles."