GCN Circular 43336
Subject
GRB 260105B: Fermi GBM Final Real-time Localization
Event
Date
2026-01-05T23:32:13Z (10 days 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 23:21:36 UT on 5 Jan 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260105B (trigger 789348101.546602 / 260105973).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 259.7, Dec = 1.7 (J2000 degrees, equivalent to J2000 17h 18m, 1d 42'), with a statistical uncertainty of 2.0 degrees.
The angle from the Fermi LAT boresight is 68.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260105973/quicklook/glg_skymap_all_bn260105973.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/bn260105973/quicklook/glg_healpix_all_bn260105973.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260105973/quicklook/glg_lc_medres34_bn260105973.gif