TITLE:   GCN CIRCULAR
NUMBER:  44703
SUBJECT: GRB 260525A: Fermi GBM Final Real-time Localization
DATE:    26/05/25 23:44:11 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 23:33:42 UT on 25 May 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260525A (trigger 801444827.592448 / 260525982).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 125.2, Dec = -44.5 (J2000 degrees, equivalent to J2000 08h 20m, -44d 30'), with a statistical uncertainty of 6.3 degrees.

The angle from the Fermi LAT boresight is 35.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260525982/quicklook/glg_skymap_all_bn260525982.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/bn260525982/quicklook/glg_healpix_all_bn260525982.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260525982/quicklook/glg_lc_medres34_bn260525982.gif