TITLE: GCN CIRCULAR NUMBER: 31306 SUBJECT: GRB 211225C: Fermi GBM Final Real-time Localization DATE: 21/12/25 18:24:37 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely SHORT GRB At 18:14:04 UT on 25 Dec 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 211225C (trigger 662148849.44199 / 211225760). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 339.9, Dec = -59.0 (J2000 degrees, equivalent to J2000 22h 39m, -59d 00'), with a statistical uncertainty of 36.0 degrees. The angle from the Fermi LAT boresight is 151.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211225760/quicklook/glg_skymap_all_bn211225760.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/bn211225760/quicklook/glg_healpix_all_bn211225760.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211225760/quicklook/glg_lc_medres34_bn211225760.gif