GCN Circular 34920

S. Bala (USRA) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 19:58:19.94 UT on 30 October 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 231030B (trigger 720388704/231030832).

The Fermi GBM Final Real-time Localization is reported in GCN 34915
Not found
 
 
.

The GBM light curve consists of a single bright peak with a duration (T90)
of about 10.8 s (50-300 keV). The time-averaged spectrum
from T0+0.003 to T0+20.544 s is best fit by
a Band function with Epeak = 240 +/- 20 keV,
alpha = -0.78 +/- 0.04, and beta = -2.02 +/- 0.08.

The event fluence (10-1000 keV) in this time interval is
(2.17 +/- 0.05)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.3 s in the 10-1000 keV band is 24.7 +/- 0.4 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/"