TITLE: GCN CIRCULAR NUMBER: 40763 SUBJECT: GRB 250617B: Fermi GBM Final Localization DATE: 25/06/18 00:14:26 GMT FROM: sumanbala2210@gmail.com The Fermi GBM team reports the detection of a likely LONG GRB "At 21:01:28.19 UT on 17 June 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250617B (trigger 771886893/250617876). It is also detected by Swift-BAT/XRT (Page et al. 2025, GCN 40760) The Fermi GBM on-ground location is consistent with the Swift-XRT position. The angle from the Fermi LAT boresight is 91 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250617876/quicklook/glg_skymap_all_bn250617876.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/bn250617876/quicklook/glg_healpix_all_bn250617876.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250617876/quicklook/glg_lc_medres34_bn250617876.gif"