[vsnet-grb-info 6537] GRB080823: Fermi Gamma-ray Burst Monitor detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8145
SUBJECT: GRB080823: Fermi Gamma-ray Burst Monitor detection
DATE:    08/08/27 16:16:58 GMT
FROM:    Sheila McBreen at MPE  <smcbreen at mpe.mpg.de>

S. McBreen , A. von Kienlin and E. Bissaldi (MPE) report on
behalf of the Fermi GBM Team:

"At 08:42:13 UT on 23 August 2008, the Fermi GBM triggered and located  
GRB 080823 (trigger 241173734 / 080823.363).
The on-ground calculated  location, using the GBM trigger data, is
 RA = 91.8 , Dec = -40.6   (J2000 degrees, equivalent to 06h 07m, -40d
36'), with an uncertainty  of 3.3 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 77 degrees.

This event comprises a small pulse at T0-3 sec, a main pulse with
substructure from 0 to 20 sec and a weaker pulse from 20 to 40 sec.   T90
(50-300 keV) is about 46 sec. The time-averaged  spectrum from T0 to
T0+18s is best fit by a power law function with an exponential high energy
cutoff. The cutoff energy,  parameterized as Epeak, is  164.7+/-34.2 keV
and the power law index is -1.2 +/-0.2. The fluence (50-300 keV) over T90
is 4.1e-6 erg/cm^2.

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