TITLE:   GCN CIRCULAR
NUMBER:  45281
SUBJECT: GRB 260804A: Fermi GBM Final Real-time Localization
DATE:    26/08/04 03:17:28 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 03:07:09 UT on 4 Aug 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260804A (trigger 807505634.188604 / 260804130).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 93.8, Dec = 18.0 (J2000 degrees, equivalent to J2000 06h 15m, 18d 00'), with a statistical uncertainty of 3.6 degrees.

The angle from the Fermi LAT boresight is 74.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260804130/quicklook/glg_skymap_all_bn260804130.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/bn260804130/quicklook/glg_healpix_all_bn260804130.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260804130/quicklook/glg_lc_medres34_bn260804130.gif