TITLE:   GCN CIRCULAR
NUMBER:  45439
SUBJECT: GRB 260825A: Fermi GBM Final Real-time Localization
DATE:    26/08/25 13:17:43 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 13:07:15 UT on 25 Aug 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260825A (trigger 809356040.919172 / 260825547).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 88.3, Dec = -1.2 (J2000 degrees, equivalent to J2000 05h 53m, -1d 11'), with a statistical uncertainty of 5.7 degrees.

The angle from the Fermi LAT boresight is 95.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260825547/quicklook/glg_skymap_all_bn260825547.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/bn260825547/quicklook/glg_healpix_all_bn260825547.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260825547/quicklook/glg_lc_medres34_bn260825547.gif