TITLE: GCN CIRCULAR NUMBER: 41482 SUBJECT: GRB 250821C: Fermi GBM Final Real-time Localization DATE: 25/08/21 23:52:36 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 23:42:00 UT on 21 Aug 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250821C (trigger 777512525.658232 / 250821988). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 104.3, Dec = -1.1 (J2000 degrees, equivalent to J2000 06h 57m, -1d 06'), with a statistical uncertainty of 15.0 degrees. The angle from the Fermi LAT boresight is 90.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250821988/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/bn250821988/q... The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250821988/q... View this GCN Circular online at https://gcn.nasa.gov/circulars/41482. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...