TITLE: GCN CIRCULAR NUMBER: 41402 SUBJECT: GRB 250818A: Fermi GBM Final Real-time Localization DATE: 25/08/18 01:42:02 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 01:31:22 UT on 18 Aug 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250818A (trigger 777173487.99771 / 250818063). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 232.7, Dec = -62.9 (J2000 degrees, equivalent to J2000 15h 30m, -62d 53'), with a statistical uncertainty of 7.8 degrees. The angle from the Fermi LAT boresight is 140.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250818063/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/bn250818063/q... The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250818063/q... View this GCN Circular online at https://gcn.nasa.gov/circulars/41402. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...