GCN Circular 43579
Subject
GRB 260131A: Fermi GBM Final Real-time Localization
Event
Date
2026-01-31T06:50:08Z (3 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 06:39:30 UT on 31 Jan 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260131A (trigger 791534375.436908 / 260131277).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 21.9, Dec = 26.9 (J2000 degrees, equivalent to J2000 01h 27m, 26d 53'), with a statistical uncertainty of 1.8 degrees.
The angle from the Fermi LAT boresight is 104.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260131277/quicklook/glg_skymap_all_bn260131277.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/bn260131277/quicklook/glg_healpix_all_bn260131277.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260131277/quicklook/glg_lc_medres34_bn260131277.gif