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GCN Circular 8100

Subject
GLAST Burst Monitor detection of GRB 080810
Date
2008-08-12T21:02:21Z (16 years ago)
From
Charles Meegan at NASA/MSFC <charles.a.meegan@nasa.gov>
C.A. Meegan (NASA/MSFC), J. Greiner (MPE), N.P. Bhat (UAH), E. Bissaldi 
(MPE), M.S. Briggs (UAH), V. Connaughton (UAH), R. Diehl (MPE), G.J. 
Fishman (NASA/MSFC), L. Gibby (NASA/MSFC), A.S. Hoover (LANL), A.J. 
van der Horst (NASA/ORAU), A. von Kienlin (MPE), R.M. Kippen (LANL), C. 
Kouveliotou (NASA/MSFC), G.G. Lichti (MPE), S. McBreen (MPE), W.S. 
Paciesas (UAH), R.D. Preece (UAH), H. Steinle (MPE), M.S. Wallace
(LANL), 
and C.A. Wilson-Hodge (NASA/MSFC)report:

"At 13:10:12 UT on 10 August 2008, the GLAST Burst Monitor (GBM) 
triggered and located GRB 080810 (GBM 080810.549, trigger 240066613), 
which was also detected by Swift (Page et al., GCN 8080Loading...
 
 ). 
The on-ground calculated location, using the GBM trigger data, is
RA, Dec 357.18, -4.61 which is equivalent to
    RA(J2000) = 23h 49m
    Dec(J2000) = -4d 37'
with an uncertainty of 5.0 degrees (radius, 1-sigma containment, 
statistical only). The angle from the Large Area Telescope (LAT) 
boresight is 61 degrees.

The GBM light curve shows a slow rise starting at T0-20, followed by 
a main emission phase comprising 5 pulses, a quiescent period and a 
sixth pulse at T0+102 s. 

The time-averaged spectrum from T-0.5 to T+53.1 sec is best fit by a 
power law function with an exponential high energy cutoff. The cutoff 
energy is 313.5 +/-73.6 keV and the power law index is -0.91 +/-0.12, 
with a reduced chi-square of 1.1 for 226 degrees of freedom. 

The fluence in the 50-300 keV band is (6.9 +/- 0.5) x 10^-6 erg/cm2. 
The 1-sec photon flux measured from T+23.5 sec in the 50-300 keV band 
is 1.85 +/- 0.16 ph/cm2/sec. All the quoted errors are at the 90% 
confidence level."