TITLE: GCN CIRCULAR NUMBER: 22049 SUBJECT: Fermi GBM trigger 530617076/171025401 is not a GRB DATE: 17/10/25 16:39:56 GMT FROM: Elisabetta Bissaldi at U.Innsbruk/IAPP E. Bissaldi (Politecnico & INFN Bari) and M. S. Briggs (UAH) report on behalf of the Fermi GBM Team: "The Fermi Gamma-ray Burst Monitor (GBM) trigger 530617076/171025401 at 09:37:51.82 UT on 25 October 2017, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is due to a terrestrial gamma-ray flash (TGF)."