GCN Circular 41845
Subject
GRB 250917A: Fermi GBM Final Real-time Localization
Event
Date
2025-09-17T02:23:49Z (6 days ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely SHORT GRB
At 02:13:13 UT on 17 Sep 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250917A (trigger 779767998.991126 / 250917093).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 14.5, Dec = -44.6 (J2000 degrees, equivalent to J2000 00h 58m, -44d 36'), with a statistical uncertainty of 21.8 degrees.
The angle from the Fermi LAT boresight is 28.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250917093/quicklook/glg_skymap_all_bn250917093.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/bn250917093/quicklook/glg_healpix_all_bn250917093.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250917093/quicklook/glg_lc_medres34_bn250917093.gif