GCN Circular 43949
Subject
GRB 260308A: Fermi GBM Final Real-time Localization
Event
Date
2026-03-08T20:16:13Z (2 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 SHORT GRB
At 20:05:52 UT on 8 Mar 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260308A (trigger 794693157.451346 / 260308837).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 250.2, Dec = -32.6 (J2000 degrees, equivalent to J2000 16h 40m, -32d 36'), with a statistical uncertainty of 3.6 degrees.
The angle from the Fermi LAT boresight is 108.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260308837/quicklook/glg_skymap_all_bn260308837.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/bn260308837/quicklook/glg_healpix_all_bn260308837.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260308837/quicklook/glg_lc_medres34_bn260308837.gif