TITLE: GCN CIRCULAR NUMBER: 29232 SUBJECT: GRB 210104A: Fermi GBM Final Real-time Localization DATE: 21/01/04 11:37:17 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 11:26:59 UT on 4 Jan 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210104A (trigger 631452424.865632 / 210104477). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 107.9, Dec = 67.1 (J2000 degrees, equivalent to J2000 07h 11m, 67d 05'), with a statistical uncertainty of 2.9 degrees. The angle from the Fermi LAT boresight is 135.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210104477/quicklook/glg_skymap_all_bn210104477.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/bn210104477/quicklook/glg_healpix_all_bn210104477.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210104477/quicklook/glg_lc_medres34_bn210104477.gif