TITLE:   GCN CIRCULAR
NUMBER:  37748
SUBJECT: GRB 241008A: Fermi GBM Observation
DATE:    24/10/09 18:34:28 GMT
FROM:    Ava Myers at NASA GSFC <ava.myers@nasa.gov>

A. Myers (NPP/GSFC) reports on behalf of the Fermi Gamma-ray Burst Monitor Team:

"At 22:00:04.35 UT on 08 October 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 241008A (trigger 750117609/241008917).
which was also detected by Fermi-LAT (Gupta et al. 2024, GCN 37747).
The Fermi GBM on-ground location is consistent with the Fermi-LAT position.

The angle from the Fermi LAT boresight is 75 degrees.

The GBM light curve consists of two peaks with a duration (T90)
of about 53 s (50-300 keV). The time-averaged spectrum
from T0 to T0+53.2 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -1.01 +/- 0.03 and the cutoff energy,
parameterized as Epeak, is 720 +/- 70 keV.

The event fluence (10-1000 keV) in this time interval is
(2.46 +/- 0.05)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+11 s in the 10-1000 keV band is 10.7 +/- 0.3 ph/s/cm^2.

A Band function fits the spectrum equally well
with Epeak= 500 +/- 100 keV, alpha = -0.96 +/- 0.04 and beta = -1.9 +/- 0.2.

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/"