TITLE:   GCN CIRCULAR
NUMBER:  41944
SUBJECT: GRB 250922B: Fermi GBM Final Real-time Localization
DATE:    25/09/22 21:24:08 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 SHORT GRB

At 21:13:25 UT on 22 Sep 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250922B (trigger 780268410.863384 / 250922884).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 48.7, Dec = 30.7 (J2000 degrees, equivalent to J2000 03h 14m, 30d 41'), with a statistical uncertainty of 13.4 degrees.

The angle from the Fermi LAT boresight is 90.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250922884/quicklook/glg_skymap_all_bn250922884.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/bn250922884/quicklook/glg_healpix_all_bn250922884.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250922884/quicklook/glg_lc_medres34_bn250922884.gif