TITLE:   GCN CIRCULAR
NUMBER:  45836
SUBJECT: GRB 261007B: Fermi GBM Final Real-time Localization
DATE:    26/10/07 13:30:45 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

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