TITLE:   GCN CIRCULAR
NUMBER:  37284
SUBJECT: GRB 240824B: Fermi GBM Observation
DATE:    24/08/25 20:38:41 GMT
FROM:    Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov>

V. Sharma (NASA GSFC/UMBC), and C. Meegan (UAH) report on behalf of the 
Fermi Gamma-ray Burst Monitor Team:

At 13:11:16.70 UT on 24 August 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240824B (trigger 746197881/240824549), which was 
also detected by MAXI/GSC detection (M. Nakajima et al., 2024, GCN 37261), 
Swift-BAT (J. DeLaunay et al. 2024, GCN 37267), and Swift-XRT (A. Tohuvavohu 
et al. 2024, GCN 37269 and J.A. Kennea et al. 2024, GCN 37270). 
The Final Real-time Localization (Fermi GBM Team 2024, GCN 37260) 
is consistent with the MAXI/GSC, and Swift.

The angle from the Fermi LAT boresight is 79 degrees.

The GBM light curve many short peaks with a duration (T90)
of about 1.5 s (50-300 keV). The time-averaged spectrum
from T0-0.96 to T0+0.90 s is best fit by a power law 
function with an exponential high-energy cutoff.
The power law index is -0.83 +/- 0.38 and the cutoff energy,
parameterized as Epeak, is 339 +/- 200 keV.

The event fluence (10-1000 keV) in this time interval is
(4 +/- 1)E-07 erg/cm^2. The 64-ms peak photon flux measured
starting from T0-0.64 s in the 10-1000 keV band is 3 +/- 1 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/"