TITLE: GCN CIRCULAR NUMBER: 44451 SUBJECT: GRB 260503A: Fermi GBM Final Real-time Localization DATE: 26/05/03 20:50:53 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 LONG GRB At 20:40:17 UT on 3 May 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260503A (trigger 799533622.581348 / 260503861). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 287.1, Dec = -2.0 (J2000 degrees, equivalent to J2000 19h 08m, -2d 00'), with a statistical uncertainty of 2.6 degrees. The angle from the Fermi LAT boresight is 30.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260503861/q... The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260503861/q... The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260503861/q... View this GCN Circular online at https://gcn.nasa.gov/circulars/44451. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...