TITLE: GCN CIRCULAR NUMBER: 43246 SUBJECT: GRB 251228A: Fermi GBM Final Real-time Localization DATE: 25/12/28 00:52:53 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely SHORT GRB At 00:42:10 UT on 28 Dec 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251228A (trigger 788575335.25706 / 251228029). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 150.2, Dec = 49.8 (J2000 degrees, equivalent to J2000 10h 00m, 49d 47'), with a statistical uncertainty of 10.7 degrees. The angle from the Fermi LAT boresight is 107.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251228029/q... The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251228029/q... The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251228029/q... View this GCN Circular online at https://gcn.nasa.gov/circulars/43246. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...