TITLE: GCN CIRCULAR NUMBER: 44859 SUBJECT: GRB 260607B: Fermi GBM Final Localization Correction DATE: 26/06/07 21:01:33 GMT FROM: Eva M. Palafox at INAOE The Fermi GBM team reports the detection of a likely LONG GRB "At 13:19:28.70 UT on 07 June 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260607B (trigger 802531173/260607555). This trigger was initially classified as Distant Particles by the flight software, but is in fact a GRB. The on-ground calculated location, using the Fermi GBM trigger data, is RA = 55.11, Dec = 26.90 (J2000 degrees, equivalent to J2000 +03h 40m, +26d 54'), with a statistical uncertainty of 1.00 degree. The angle from the Fermi LAT boresight is 68 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260607555/quicklook/glg_skymap_all_bn260607555.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260607555/quicklook/glg_healpix_all_bn260607555.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260607555/quicklook/glg_lc_medres34_bn260607555.gif"