TITLE: GCN CIRCULAR NUMBER: 23068 SUBJECT: Fermi GBM trigger 554730582/180731493 is not a GRB DATE: 18/07/31 14:38:42 GMT FROM: Andreas von Kienlin at MPE A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team: "The Fermi Gamma-ray Burst Monitor (GBM) trigger 554730582/180731493 at 11:49:37.31 UT on 31 July 2018, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is due to a terrestrial gamma-ray flash (TGF)."