TITLE: GCN CIRCULAR NUMBER: 33091 SUBJECT: GRB 221221A: Fermi GBM Final Real-time Localization DATE: 22/12/21 22:49:56 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 22:39:30 UT on 21 Dec 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 221221A (trigger 693355175.568406 / 221221944). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 81.8, Dec = 63.4 (J2000 degrees, equivalent to J2000 05h 27m, 63d 23'), with a statistical uncertainty of 2.7 degrees. The angle from the Fermi LAT boresight is 116.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221221944/quicklook/glg_skymap_all_bn221221944.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221221944/quicklook/glg_healpix_all_bn221221944.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221221944/quicklook/glg_lc_medres34_bn221221944.gif