TITLE: GCN CIRCULAR NUMBER: 30671 SUBJECT: GRB 210821A: Fermi GBM Final Real-time Localization DATE: 21/08/21 07:51:40 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 07:40:28 UT on 21 Aug 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210821A (trigger 651224433.594692 / 210821320). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 49.3, Dec = -6.9 (J2000 degrees, equivalent to J2000 03h 17m, -6d 54'), with a statistical uncertainty of 2.0 degrees. The angle from the Fermi LAT boresight is 87.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210821320/quicklook/glg_skymap_all_bn210821320.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210821320/quicklook/glg_healpix_all_bn210821320.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210821320/quicklook/glg_lc_medres34_bn210821320.gif