TITLE: GCN CIRCULAR NUMBER: 33910 SUBJECT: GRB 230603A: Fermi GBM Final Real-time Localization DATE: 23/06/03 12:45:56 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 12:35:29 UT on 3 Jun 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230603A (trigger 707488534.44648 / 230603525). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 294.5, Dec = -11.6 (J2000 degrees, equivalent to J2000 19h 37m, -11d 35'), with a statistical uncertainty of 3.6 degrees. The angle from the Fermi LAT boresight is 38.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230603525/quicklook/glg_skymap_all_bn230603525.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230603525/quicklook/glg_healpix_all_bn230603525.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230603525/quicklook/glg_lc_medres34_bn230603525.gif