TITLE: GCN CIRCULAR NUMBER: 40501 SUBJECT: GRB 250520B: Fermi GBM Final Real-time Localization DATE: 25/05/20 10:46:39 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 10:36:02 UT on 20 May 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250520B (trigger 769430167.408886 / 250520442). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 100.6, Dec = 68.7 (J2000 degrees, equivalent to J2000 06h 42m, 68d 42'), with a statistical uncertainty of 4.3 degrees. The angle from the Fermi LAT boresight is 21.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250520442/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/bn250520442/q... The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250520442/q... View this GCN Circular online at https://gcn.nasa.gov/circulars/40501. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...