TITLE:   GCN CIRCULAR
NUMBER:  38265
SUBJECT: GRB 241117A: Fermi GBM Detection
DATE:    24/11/17 20:47:14 GMT
FROM:    Lorenzo Scotton at UAH <lscottongcn@outlook.com>

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

"At 03:00:43.23 UT on 17 November 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 241117A (trigger 753505248/241117125).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 2.04, Dec = 16.33 (J2000 degrees, equivalent to
J2000 0h 8m, +16d 19'), with a statistical uncertainty of 1.74 degrees.
(radius, 1-sigma containment, statistical only; there is additionally a
systematic error which we have characterized as a mixture of two Gaussians,
one with a radius of 1.8 degrees (52% contribution) and one with a radius
of 4.1 degrees (47% contribution) [A. Goldstein et al. 2020, ApJ, 895, 1]).

The angle from the Fermi LAT boresight is 58 degrees.

The GBM light curve consists of a single emission episode with a duration (T90)
of about 8.9 s (50-300 keV). The time-averaged spectrum
from T0-0.3 to T0+9.86 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.46 +/- 0.07 and the cutoff energy,
parameterized as Epeak, is 724 +/- 62 keV.

The event fluence (10-1000 keV) in this time interval is
(9.7 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.58 s in the 10-1000 keV band is 13.2 +/- 0.3 ph/s/cm^2.

A Band function fits the spectrum equally well with
Epeak = 708 +/- 68 keV, alpha = -0.45 +/- 0.07 and beta = -3.16 +/- 0.98.

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/"