TITLE:   GCN CIRCULAR
NUMBER:  45761
SUBJECT: GRB 260926A: Fermi GBM Final Real-time Localization
DATE:    26/09/26 16:30:40 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 16:20:14 UT on 26 Sep 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260926A (trigger 812132419.655086 / 260926681).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 20.2, Dec = 65.3 (J2000 degrees, equivalent to J2000 01h 20m, 65d 17'), with a statistical uncertainty of 5.8 degrees.

The angle from the Fermi LAT boresight is 81.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260926681/quicklook/glg_skymap_all_bn260926681.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/bn260926681/quicklook/glg_healpix_all_bn260926681.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260926681/quicklook/glg_lc_medres34_bn260926681.gif