TITLE:   GCN CIRCULAR
NUMBER:  42533
SUBJECT: GRB 251102B: Fermi GBM Final Real-time Localization
DATE:    25/11/02 21:26:26 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 21:15:53 UT on 2 Nov 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251102B (trigger 783810958.850558 / 251102886).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 110.6, Dec = -69.7 (J2000 degrees, equivalent to J2000 07h 22m, -69d 42'), with a statistical uncertainty of 4.2 degrees.

The angle from the Fermi LAT boresight is 153.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251102886/quicklook/glg_skymap_all_bn251102886.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/bn251102886/quicklook/glg_healpix_all_bn251102886.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251102886/quicklook/glg_lc_medres34_bn251102886.gif