GCN Circular 43335
Subject
GRB 260105A: Fermi GBM Final Real-time Localization
Event
Date
2026-01-05T22:57:42Z (12 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 22:47:11 UT on 5 Jan 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260105A (trigger 789346036.667754 / 260105949).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 64.5, Dec = 55.5 (J2000 degrees, equivalent to J2000 04h 17m, 55d 30'), with a statistical uncertainty of 3.3 degrees.
The angle from the Fermi LAT boresight is 99.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260105949/quicklook/glg_skymap_all_bn260105949.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/bn260105949/quicklook/glg_healpix_all_bn260105949.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260105949/quicklook/glg_lc_medres34_bn260105949.gif