TITLE:   GCN CIRCULAR
NUMBER:  34199
SUBJECT: GRB 230709C: Fermi GBM Detection
DATE:    23/07/10 20:12:24 GMT
FROM:    Peter Veres at University of Alabama in Huntsville <veresp@gmail.com>


P. Veres  and C. Meegan (both UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 17:38:26.82 UT on 09 July 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230709C (trigger 710617111/230709735).

The on-ground calculated location, using the Fermi GBM trigger data (GCN #34198) is consistent with the location reported by Preis et al., GCN #34187.

The GBM light curve consists of a single emission episode with a duration (T90)
of about 0.19 s (50-300 keV). The time-averaged spectrum
from T0-0.06 to T0+0.19 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.01 +/- 0.07 and the cutoff energy,
parameterized as Epeak, is 1050 +/- 50 keV.

The event fluence (10-1000 keV) in this time interval is
(6.3 +/- 0.1)E-06 erg/cm^2. The 64-ms peak photon flux measured
starting from T0+0.0 s in the 10-1000 keV band is 58 +/- 3 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"