TITLE: GCN CIRCULAR NUMBER: 40025 SUBJECT: GRB 250403A: Fermi GBM Final Real-time Localization DATE: 25/04/03 15:26:06 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 15:15:22 UT on 3 Apr 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250403A (trigger 765386127.830438 / 250403636). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 204.2, Dec = -25.4 (J2000 degrees, equivalent to J2000 13h 36m, -25d 23'), with a statistical uncertainty of 5.1 degrees. The angle from the Fermi LAT boresight is 56.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250403636/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/bn250403636/q... The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250403636/q... View this GCN Circular online at https://gcn.nasa.gov/circulars/40025. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...