Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 32479

GRB 220823A: Fermi GBM detection
2022-08-24T16:43:38Z (2 years ago)
Boyan A. Hristov at UAH <>
B. Hirstov (UAH) and C. Fletcher (USRA)
report on behalf of the Fermi GBM Team:

"At 03:28:52.39 UT on 23 August 2022, the Fermi Gamma-Ray
Burst Monitor (GBM) triggered and located GRB 220823A
(trigger 682918137 / 220823145),which was also detected by
Swift/BAT-GUANO (A. Tohuvavohu et al. 2022, GCN 32476).

The on-ground calculated location, using the GBM trigger
data, is RA = 82.94, DEC = +2.44 (J2000 degrees, equivalent
to 05h, 31m, 2d 26'), with a statistical uncertainty of 3
degrees (radius, 1-sigma containment, statistical only;
there is additionally a systematic error which we have
characterized as a core-plus-tail model, with 90% of GRBs
having a 3.7 deg error and a small tail suffering a larger
than 10 deg systematic error. [Connaughton et al. 2015,
ApJS, 216, 32] ).

The angle from the Fermi LAT boresight at the GBM trigger
time is 15 degrees.

The GBM light curve consists of single peak with a duration
(T90) of 1.1 +/- 0.7 s (50-300 keV).

The time-averaged spectrum from T0-1.024 s to T0+0.256 s is
best fit by a power law with an exponential cutoff with
Epeak = 1189 +/- 608 keV and alpha = -0.52 +/- 0.26.

The event fluence (10-1000 keV) in this time interval is
(1.1 +/- 0.1)E-6 erg/cm^2. The 0.064-sec peak photon flux
measured starting from T0-0.064 s in the 10-1000 keV band
is 5 +/- 1 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:

For Fermi GBM data and info, please visit the official
Fermi GBM Support Page:"
Looking for U.S. government information and services? Visit