GCN Circular 46044
Subject
GRB 261026C: Fermi GBM Final Real-time Localization
Event
Date
2026-10-26T14:05:13Z (6 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 13:55:43 UT on 26 Oct 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 261026C (trigger 814715748.208736 / 261026580).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 129.1, Dec = 7.0 (J2000 degrees, equivalent to J2000 08h 36m, 7d 00'), with a statistical uncertainty of 3.8 degrees.
The angle from the Fermi LAT boresight is 45.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261026580/quicklook/glg_skymap_all_bn261026580.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/bn261026580/quicklook/glg_healpix_all_bn261026580.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261026580/quicklook/glg_lc_medres34_bn261026580.gif