TITLE: GCN CIRCULAR NUMBER: 33566 SUBJECT: GRB 230405A: Fermi GBM Final Real-time Localization DATE: 23/04/05 15:13:37 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 15:03:04 UT on 5 Apr 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230405A (trigger 702399789.583538 / 230405627). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 341.9, Dec = 77.0 (J2000 degrees, equivalent to J2000 22h 47m, 77d 00'), with a statistical uncertainty of 5.6 degrees. The angle from the Fermi LAT boresight is 138.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230405627/quicklook/glg_skymap_all_bn230405627.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/bn230405627/quicklook/glg_healpix_all_bn230405627.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230405627/quicklook/glg_lc_medres34_bn230405627.gif