TITLE:   GCN CIRCULAR
NUMBER:  42112
SUBJECT: GRB 251005B: Fermi GBM Final Real-time Localization
DATE:    25/10/05 14:37:49 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 14:27:19 UT on 5 Oct 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251005B (trigger 781367244.128264 / 251005602).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 298.6, Dec = -8.9 (J2000 degrees, equivalent to J2000 19h 54m, -8d 54'), with a statistical uncertainty of 6.5 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/2025/bn251005602/quicklook/glg_skymap_all_bn251005602.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251005602/quicklook/glg_healpix_all_bn251005602.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251005602/quicklook/glg_lc_medres34_bn251005602.gif