TITLE:   GCN CIRCULAR
NUMBER:  45764
SUBJECT: GRB 260926B: Fermi GBM Final Real-time Localization
DATE:    26/09/26 19:06:22 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 SHORT GRB

At 18:55:49 UT on 26 Sep 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260926B (trigger 812141754.92478 / 260926789).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 184.2, Dec = 4.8 (J2000 degrees, equivalent to J2000 12h 16m, 4d 47'), with a statistical uncertainty of 11.6 degrees.

The angle from the Fermi LAT boresight is 100.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260926789/quicklook/glg_skymap_all_bn260926789.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/bn260926789/quicklook/glg_healpix_all_bn260926789.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260926789/quicklook/glg_lc_medres34_bn260926789.gif