TITLE: GCN CIRCULAR NUMBER: 42836 SUBJECT: GRB 251125B: Fermi GBM Final Real-time Localization DATE: 25/11/25 20:34:30 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 LONG GRB At 20:23:45 UT on 25 Nov 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251125B (trigger 785795030.880336 / 251125850). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 237.5, Dec = 57.5 (J2000 degrees, equivalent to J2000 15h 50m, 57d 30'), with a statistical uncertainty of 3.1 degrees. The angle from the Fermi LAT boresight is 45.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251125850/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/bn251125850/q... The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251125850/q... View this GCN Circular online at https://gcn.nasa.gov/circulars/42836. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...