TITLE: GCN CIRCULAR NUMBER: 43358 SUBJECT: GRB 260109B: Fermi GBM Final Real-time Localization DATE: 26/01/09 08:52:04 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely LONG GRB At 08:41:22 UT on 9 Jan 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260109B (trigger 789640887.356258 / 260109362). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 197.5, Dec = -73.9 (J2000 degrees, equivalent to J2000 13h 09m, -73d 54'), with a statistical uncertainty of 13.7 degrees. The angle from the Fermi LAT boresight is 54.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260109362/q... The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260109362/q... The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260109362/q... View this GCN Circular online at https://gcn.nasa.gov/circulars/43358. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...