TITLE: GCN CIRCULAR NUMBER: 41473 SUBJECT: GRB 250821B: Fermi GBM Final Localization of a Bright Burst DATE: 25/08/21 19:00:29 GMT FROM: Jacob Smith at Fermi-GBM Team <jrs0118@uah.edu> The Fermi GBM team reports the detection of a likely LONG GRB "At 16:07:47.46 UT on 21 August 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250821B (trigger 777485272/250821672). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 39.95, Dec = -77.13 (J2000 degrees, equivalent to J2000 2h 39m, -77d 7'), with a statistical uncertainty of 1.00 degrees. The angle from the Fermi LAT boresight is 67 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250821672/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/bn250821672/q... The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250821672/q..." View this GCN Circular online at https://gcn.nasa.gov/circulars/41473. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...