TITLE: GCN CIRCULAR NUMBER: 42449 SUBJECT: GRB 251025C: Fermi GBM Final Real-time Localization DATE: 25/10/25 23:19:13 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 23:08:40 UT on 25 Oct 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251025C (trigger 783126525.293544 / 251025964). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 170.7, Dec = 54.9 (J2000 degrees, equivalent to J2000 11h 22m, 54d 53'), with a statistical uncertainty of 2.2 degrees. The angle from the Fermi LAT boresight is 103.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251025964/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/bn251025964/q... The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251025964/q... View this GCN Circular online at https://gcn.nasa.gov/circulars/42449. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...