GCN Circular 41819
Subject
GRB 250912A: Fermi GBM Final Real-time Localization
Event
Date
2025-09-12T21:17:50Z (10 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 LONG GRB
At 21:06:23 UT on 12 Sep 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250912A (trigger 779403988.636734 / 250912879).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 13.9, Dec = 24.3 (J2000 degrees, equivalent to J2000 00h 55m, 24d 18'), with a statistical uncertainty of 7.9 degrees.
The angle from the Fermi LAT boresight is 62.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250912879/quicklook/glg_skymap_all_bn250912879.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/bn250912879/quicklook/glg_healpix_all_bn250912879.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250912879/quicklook/glg_lc_medres34_bn250912879.gif