GCN Circular 15554

Subject: GRB 131128A: Fermi GBM observation

Hoi-Fung Yu (MPE) reports on behalf of the Fermi GBM Team:

"At 15:06:25.28 UT on 28 November 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 131128A (trigger 407343988 / 131128629), which
was also detected by the Swift/BAT (Sonbas et al., GCN 15533
Not found
 
 
). This burst,
tentatively classified as a particle event by the FSW onboard, is in fact
a gamma-ray burst. The GBM on-ground location is consistent with the 
Swift/XRT position.

The angle from the Fermi LAT boresight is 71 degrees.

The GBM light curve consists of a single pulse with a duration (T90) of 
~2.0 s (50-300 keV). The time-averaged spectrum from T0-1.024 s 
to T0+2.560 s is adequately fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.9 +/- 0.3 and the cutoff 
energy, parameterized as Epeak, is 61.0 +/- 9.0 keV.

The event fluence (10-1000 keV) in this time interval is
(4.4 +/- 0.5)E-07 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.83 s in the 10-1000 keV band is 3.8 +/- 0.3 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."