GCN Circular 45772
Subject
GRB 260928A: Fermi GBM Final Real-time Localization
Event
Date
2026-09-28T00:41:50Z (21 hours 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 SHORT GRB
At 00:31:16 UT on 28 Sep 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260928A (trigger 812248281.78187 / 260928022).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 290.5, Dec = 8.1 (J2000 degrees, equivalent to J2000 19h 22m, 8d 05'), with a statistical uncertainty of 9.8 degrees.
The angle from the Fermi LAT boresight is 44.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260928022/quicklook/glg_skymap_all_bn260928022.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/bn260928022/quicklook/glg_healpix_all_bn260928022.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260928022/quicklook/glg_lc_medres34_bn260928022.gif