TITLE:   GCN CIRCULAR
NUMBER:  37945
SUBJECT: GRB 241029A: Fermi GBM Observation
DATE:    24/10/29 18:20:11 GMT
FROM:    Ava Myers at NASA GSFC <ava.myers@nasa.gov>

A. Myers (NPP/GSFC), M. Godwin (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team:

At 02:19:59.87 UT on 29 October 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 241029A (trigger 751861204/241029097).
which was also detected by SVOM/ECLAIRs (S. Schanne et al., GCN [37934](https://gcn.nasa.gov/circulars/37934)).
The Fermi GBM on-ground location is consistent with the SVOM position.

The angle from the Fermi LAT boresight is 76 degrees.

The GBM light curve consists of multiple peaks with a duration (T90)
of about 13.3 s (50-300 keV). The time-averaged spectrum
from T0 to T0+13.152 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -1.01 +/- 0.04 and the cutoff energy,
parameterized as Epeak, is 220 +/- 10 keV.

The event fluence (10-1000 keV) in this time interval is
(9.2 +/- 0.3)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.064 s in the 10-1000 keV band is 9.6 +/- 0.4 ph/s/cm^2.

A Band function fits the spectrum equally well
with Epeak= 190 +/- 20 keV, alpha = -0.96 +/- 0.05 and beta = -2.5 +/- 0.3.

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/