TITLE: GCN CIRCULAR NUMBER: 30763 SUBJECT: GRB 210904A: Fermi GBM Final Real-time Localization DATE: 21/09/04 20:58:06 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 SHORT GRB At 20:47:39 UT on 4 Sep 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210904A (trigger 652481264.630844 / 210904866). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 121.1, Dec = -44.0 (J2000 degrees, equivalent to J2000 08h 04m, -44d 00'), with a statistical uncertainty of 9.2 degrees. The angle from the Fermi LAT boresight is 104.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210904866/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/bn210904866/q... The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210904866/q...