TITLE:   GCN CIRCULAR
NUMBER:  42380
SUBJECT: GRB 251022A: Fermi GBM Final Real-time Localization
DATE:    25/10/22 22:44:50 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 22:34:15 UT on 22 Oct 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251022A (trigger 782865260.264246 / 251022940).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 74.5, Dec = -22.7 (J2000 degrees, equivalent to J2000 04h 58m, -22d 41'), with a statistical uncertainty of 1.9 degrees.

The angle from the Fermi LAT boresight is 29.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251022940/quicklook/glg_skymap_all_bn251022940.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/bn251022940/quicklook/glg_healpix_all_bn251022940.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251022940/quicklook/glg_lc_medres34_bn251022940.gif