GCN Circular 41933
Subject
GRB 250922A: Fermi GBM Final Localization
Event
Date
2025-09-22T04:52:19Z (9 days ago)
Edited On
2025-09-22T13:31:03Z (9 days ago)
From
rhamburg@usra.edu
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>
Via
Web form
The Fermi GBM team reports the detection of a likely LONG GRB
"At 03:07:21.46 UT on 22 September 2025, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 250922A (trigger 780203246/250922130).
This trigger was initially classified as Below Horizon by the flight software,
but is in fact a GRB.
The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 353.54, Dec = 0.42 (J2000 degrees, equivalent to J2000 23h 34m, +0d 25'),
with a statistical uncertainty of 6.13 degrees.
The angle from the Fermi LAT boresight is 86 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250922130/quicklook/glg_skymap_all_bn250922130.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/bn250922130/quicklook/glg_healpix_all_bn250922130.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250922130/quicklook/glg_lc_medres34_bn250922130.gif"