TITLE:   GCN CIRCULAR
NUMBER:  43316
SUBJECT: GRB 260104B: Fermi GBM Final Localization
DATE:    26/01/04 07:50:23 GMT
FROM:    Rushikesh Sonawane  at IISER, TVM <rushikesh23@iisertvm.ac.in>

The Fermi GBM team reports the detection of a likely LONG GRB

"At 05:49:57.62 UT on 04 January 2026, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 260104B (trigger 789198602/260104243).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 87.42, Dec = -29.65 (J2000 degrees, equivalent to J2000 05h 49m, -29d 39'),
with a statistical uncertainty of 10.28 degrees.

The angle from the Fermi LAT boresight is 42 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260104243/quicklook/glg_skymap_all_bn260104243.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/bn260104243/quicklook/glg_healpix_all_bn260104243.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260104243/quicklook/glg_lc_medres34_bn260104243.gif"