GCN Circular 42179

The Fermi GBM team reports the detection of a likely SHORT GRB

"At 15:58:56.61 UT on 09 October 2025, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 251009A (trigger 781718341/251009666).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 72.05, Dec = -25.84 (J2000 degrees, equivalent to J2000 4h 48m, -25d 50'),
with a statistical uncertainty of 25.22 degrees.

The angle from the Fermi LAT boresight is 86 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251009666/quicklook/glg_skymap_all_bn251009666.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/bn251009666/quicklook/glg_healpix_all_bn251009666.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251009666/quicklook/glg_lc_medres34_bn251009666.gif"