TITLE: GCN CIRCULAR NUMBER: 19090 SUBJECT: Fermi GBM trigger 478156376/16022621 is not a GRB DATE: 16/02/26 13:39:49 GMT FROM: Elisabetta Bissaldi at U.Innsbruk/IAPP E.Bissaldi (Politecnico & INFN Bari) reports on behalf of the Fermi GBM Team: "The Fermi Gamma-ray Burst Monitor (GBM) trigger 478156376/16022621 at 05:12:52.31 UT on 26 February 2016, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is due to particle activity."