TITLE: GCN CIRCULAR NUMBER: 15604 SUBJECT: Fermi Gamma-ray Burst Monitor trigger 409187680/131219968 is not a GRB DATE: 13/12/20 00:56:49 GMT FROM: Binbin Zhang at UAH Bin-Bin Zhang (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: “The Fermi Gamma-ray Burst Monitor (GBM) trigger 409187680 / 131219968 at 23:14:37.68 UT on 19 December 2013, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is due to a solar flare.”