TITLE:   GCN CIRCULAR
NUMBER:  43284
SUBJECT: GRB 260101A: Fermi GBM Final Real-time Localization
DATE:    26/01/01 01:07:07 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 00:56:30 UT on 1 Jan 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260101A (trigger 788921795.64985 / 260101039).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 83.7, Dec = 64.0 (J2000 degrees, equivalent to J2000 05h 34m, 64d 00'), with a statistical uncertainty of 3.6 degrees.

The angle from the Fermi LAT boresight is 43.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260101039/quicklook/glg_skymap_all_bn260101039.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/bn260101039/quicklook/glg_healpix_all_bn260101039.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260101039/quicklook/glg_lc_medres34_bn260101039.gif