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GCN Circular 34357

GRB 230805B: Fermi GBM observation
2023-08-07T14:40:05Z (a year ago)
Joe Mangan at IJCLab <>
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J.Mangan (CNRS/IJCLab) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:

"At 11:23:33.59 UT on 05 August 2023, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 230805B (trigger 712927418 / 230805475),
which was also detected by Swift BAT (S. B. Cenko et al. 2023, GCN 34339).
The Fermi GBM on-ground location is consistent with the Swift BAT position.

The angle from the Fermi LAT boresight at the GBM trigger time is 48 degrees.

The GBM light curve consists of multiple emissions
with a duration (T90) of about 60 s (50-300 keV).
The time-averaged spectrum from T0-0 s to T0+60.5 s is best fit by
a simple power law function with index -1.4 +/- 0.03

The event fluence (10-1000 keV) in this time interval is
(4.8 +/- 0.3)E-6 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+-0.1 s in the 10-1000 keV band
is 2.3 +/- 0.2 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:"
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