TITLE: GCN CIRCULAR NUMBER: 17984 SUBJECT: Fermi Gamma-ray Burst Monitor Trigger bn150628857 is not a GRB DATE: 15/06/30 16:05:25 GMT FROM: Binbin Zhang at UAH Bin-Bin Zhang (UAH) reports on behalf of the Fermi GBM Team: "The Fermi Gamma-ray Burst Monitor (GBM) trigger bn150628857 at 20:33:39.177 UT on 28 June 2015, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is due to particle activity."