GCN Circular 45836
Subject
GRB 261007B: Fermi GBM Final Real-time Localization
Event
Date
2026-10-07T13:30:45Z (11 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 LONG GRB
At 13:20:18 UT on 7 Oct 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 261007B (trigger 813072023.698636 / 261007556).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 222.2, Dec = -54.1 (J2000 degrees, equivalent to J2000 14h 48m, -54d 06'), with a statistical uncertainty of 9.1 degrees.
The angle from the Fermi LAT boresight is 49.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261007556/quicklook/glg_skymap_all_bn261007556.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/bn261007556/quicklook/glg_healpix_all_bn261007556.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261007556/quicklook/glg_lc_medres34_bn261007556.gif