TITLE:   GCN CIRCULAR
NUMBER:  43477
SUBJECT: GRB 260120B: Fermi GBM Final Real-time Localization
DATE:    26/01/20 18:10:48 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 18:00:26 UT on 20 Jan 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260120B (trigger 790624831.046372 / 260120750).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 282.2, Dec = 64.2 (J2000 degrees, equivalent to J2000 18h 48m, 64d 12'), with a statistical uncertainty of 1.5 degrees.

The angle from the Fermi LAT boresight is 11.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260120750/quicklook/glg_skymap_all_bn260120750.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/bn260120750/quicklook/glg_healpix_all_bn260120750.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260120750/quicklook/glg_lc_medres34_bn260120750.gif