TITLE:   GCN CIRCULAR
NUMBER:  42069
SUBJECT: GRB 251003A: Fermi GBM Final Real-time Localization
DATE:    25/10/03 02:09:08 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 01:58:31 UT on 3 Oct 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251003A (trigger 781149516.956282 / 251003082).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 31.9, Dec = 49.6 (J2000 degrees, equivalent to J2000 02h 07m, 49d 36'), with a statistical uncertainty of 18.2 degrees.

The angle from the Fermi LAT boresight is 64.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251003082/quicklook/glg_skymap_all_bn251003082.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/bn251003082/quicklook/glg_healpix_all_bn251003082.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251003082/quicklook/glg_lc_medres34_bn251003082.gif