TITLE: GCN CIRCULAR NUMBER: 39703 SUBJECT: GRB 250313A: Fermi GBM Final Real-time Localization DATE: 25/03/13 14:44:53 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 14:34:33 UT on 13 Mar 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250313A (trigger 763569278.689058 / 250313607). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 276.4, Dec = 51.8 (J2000 degrees, equivalent to J2000 18h 25m, 51d 47'), with a statistical uncertainty of 1.0 degrees. The angle from the Fermi LAT boresight is 4.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250313607/quicklook/glg_skymap_all_bn250313607.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250313607/quicklook/glg_healpix_all_bn250313607.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250313607/quicklook/glg_lc_medres34_bn250313607.gif