GCN Circular 8589

P. N. Bhat (UAH) and A.J. van der Horst (NASA/ORAU)
report on behalf of the Fermi GBM Team:

"At 21:34:09.06 UT on 26th November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB081126 (trigger 249428050 / 081126899) which was
also detected by the SWIFT-BAT (Margutti et al. 2008, GCN Circular 8554
Not found
 
 
)
 
The angle from the Fermi LAT boresight is 18 degrees.

This burst was also independently detected by INTEGRAL SPI-ACS and
Konus/Wind (Golenetskii et al., 2008, GCN Circular 8562
Not found
 
 
).

The GBM light curve consists of two pulses separated by
about 30 s with almost no emission in between. There is
also a weak untriggered emission at about T0-20 s.
The burst duration (T90) is about 56 s (8-1000 keV).
The time-averaged spectrum of the first pulse from T0 s to T0+11 s is
well fit by a Band function with Epeak = 192 +/- 74 keV,
alpha = -0.3 +/- 0.4, and beta = -1.6 +/- 0.1.(chi squared 547 for 487
d.o.f.) 

Similarly the second pulse from about 20 s to 40 s is also
well fit by a Band function with Epeak = 162 +/- 77 keV,
alpha = -0.3 +/- 0.5, and beta = -1.6 +/- 0.1.
(chi squared 539 for 487 d.o.f.). The time averaged spectrum of the
entire burst is well fit by a Band function with Epeak = 176 +/- 84 keV,
alpha = -0.3 +/- 0.5, and beta = -1.7 +/- 0.1. (chi squared 464 for 487
d.o.f.)

The event fluences (8-1000 keV) in the two pulses are
(2.7 +/- 0.8)E-07 erg/cm^2 and (1.9 +/- 0.8)E-07 erg/cm^2
respectively. The 1-sec peak photon fluxes in the 8-1000 keV
band in the two pulses are 1.3+/- 0.4 ph/s/cm^2 and 1.0 +/- 0.4
ph/s/cm^2 respectively. The total event fluence (8-1000 keV) is
(1.5 +/- 0.6)E-07 erg/cm^2. The 1-sec peak photon fluxes in the 8-1000 keV
band in the two pulses are 0.7+/- 0.3 ph/s/cm^2
 

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