TITLE:   GCN CIRCULAR
NUMBER:  44226
SUBJECT: GRB 260407A: Fermi GBM Final Real-time Localization
DATE:    26/04/07 09:21:29 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 09:11:07 UT on 7 Apr 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260407A (trigger 797245872.223582 / 260407383).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 71.4, Dec = 28.2 (J2000 degrees, equivalent to J2000 04h 45m, 28d 11'), with a statistical uncertainty of 2.1 degrees.

The angle from the Fermi LAT boresight is 61.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260407383/quicklook/glg_skymap_all_bn260407383.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/bn260407383/quicklook/glg_healpix_all_bn260407383.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260407383/quicklook/glg_lc_medres34_bn260407383.gif