TITLE: GCN CIRCULAR NUMBER: 30880 SUBJECT: GRB 210925A: Fermi GBM Final Real-time Localization DATE: 21/09/25 19:22:53 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 19:12:27 UT on 25 Sep 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210925A (trigger 654289952.965146 / 210925800). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 347.4, Dec = -17.1 (J2000 degrees, equivalent to J2000 23h 09m, -17d 06'), with a statistical uncertainty of 3.3 degrees. The angle from the Fermi LAT boresight is 82.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210925800/q... The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210925800/q... The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210925800/q...