TITLE:   GCN CIRCULAR
NUMBER:  43528
SUBJECT: GRB 260127A: Fermi GBM Final Real-time Localization
DATE:    26/01/27 18:01:38 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 17:51:07 UT on 27 Jan 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260127A (trigger 791229072.735026 / 260127744).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 226.9, Dec = -2.2 (J2000 degrees, equivalent to J2000 15h 07m, -2d 12'), with a statistical uncertainty of 5.1 degrees.

The angle from the Fermi LAT boresight is 79.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260127744/quicklook/glg_skymap_all_bn260127744.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/bn260127744/quicklook/glg_healpix_all_bn260127744.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260127744/quicklook/glg_lc_medres34_bn260127744.gif