GCN Circular 45279
Subject
GRB 260803A: Fermi GBM Final Real-time Localization
Event
Date
2026-08-03T17:39:21Z (20 days ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely LONG GRB
At 17:28:46 UT on 3 Aug 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260803A (trigger 807470931.896978 / 260803728).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 22.1, Dec = 68.7 (J2000 degrees, equivalent to J2000 01h 28m, 68d 42'), with a statistical uncertainty of 6.7 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/bn260803728/quicklook/glg_skymap_all_bn260803728.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/bn260803728/quicklook/glg_healpix_all_bn260803728.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260803728/quicklook/glg_lc_medres34_bn260803728.gif