[vsnet-grb-info 7002] GRB 081129: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8586
SUBJECT: GRB 081129: Fermi GBM detection
DATE:    08/12/01 11:08:37 GMT
FROM:    Andreas von Kienlin at MPE  <azk at mpe.mpg.de>

A. von Kienlin (MPE)  
reports on behalf of the Fermi GBM Team: 

"At 03:52:04.26 UT on 29 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081129 (trigger 249623525 / 081129161).

The on-ground calculated location, using the GBM trigger 
data, is RA = 55.0, DEC = -63.0 (J2000 degrees, 
equivalent to 03h 40m, -63d 00'), with an uncertainty 
of 1.9 degrees (radius, 1-sigma containment, 
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
 
The angle from the Fermi LAT boresight is 118 degrees.

This burst was also independently detected by INTEGRAL SPI-ACS.

The GBM light curve contains 2 peaks and has a duration (T90) 
of about 59 s (8-1000 keV) and (T50) of about 17 s (8-1000 keV).
The time-averaged spectrum from T0+0.003 s to T0+59.521 s is 
best fit by a Band function with Epeak = 150 +/- 30 keV, 
alpha = -0.5 +/- 0.2, and beta = -1.84 +/- 0.08
(chi squared 253 for 233 d.o.f.).
The event fluence (8-1000 keV) in this time interval is 
(2.0 +/- 0.3)E-05 erg/cm^2. The 1-sec photon flux measured 
starting from T0 s in the 8-1000 keV band 
is 14 +/- 3 ph/s/cm^2.

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