GCN Circular 42865
Subject
GRB 251128A: Fermi GBM Final Real-time Localization
Event
Date
2025-11-28T04:33:00Z (a day 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 04:22:21 UT on 28 Nov 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251128A (trigger 785996546.612178 / 251128182).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 117.5, Dec = 52.2 (J2000 degrees, equivalent to J2000 07h 49m, 52d 12'), with a statistical uncertainty of 2.0 degrees.
The angle from the Fermi LAT boresight is 114.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251128182/quicklook/glg_skymap_all_bn251128182.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/bn251128182/quicklook/glg_healpix_all_bn251128182.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251128182/quicklook/glg_lc_medres34_bn251128182.gif