TITLE: GCN CIRCULAR NUMBER: 33116 SUBJECT: GRB 221228A: Fermi GBM Final Real-time Localization DATE: 22/12/28 05:03:37 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 04:53:14 UT on 28 Dec 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 221228A (trigger 693895999.795578 / 221228204). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 290.2, Dec = 13.8 (J2000 degrees, equivalent to J2000 19h 20m, 13d 48'), with a statistical uncertainty of 5.4 degrees. The angle from the Fermi LAT boresight is 46.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221228204/quicklook/glg_skymap_all_bn221228204.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/bn221228204/quicklook/glg_healpix_all_bn221228204.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221228204/quicklook/glg_lc_medres34_bn221228204.gif