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GCN Circular 400

Subject

GRB990806: BATSE Observations

Date

1999-08-10T16:33:14Z (25 years ago)

From

Timothy Giblin at MSFC <giblin@bowie.msfc.nasa.gov>

T. Giblin, G. Richardson, and R. M. Kippen (University of Alabama
in Huntsville) report on behalf of the BATSE GRB Team:


GRB990806 was detected by BATSE on 1999 August 6.60285 UT as trigger 
7701. The time profile of the burst exhibits a FRED-like structure 
(fast rise and slower decay) with some variability on shorter time 
scales. The T50 and T90 durations are 4.93 (+/- 0.26) and 17.41 
(+/- 3.84) seconds, respectively. The peak flux of the burst, 
integrated over 1.024 s in the 50-300 keV range, is 1.60 (+/- 0.05) 
photons cmE-2 sE-1, placing it in the top 28% of the BATSE peak flux 
distribution. The fluence (>20 keV) of the burst is 3.29 (+/- 0.53) 
x 10E-6 erg cmE-2, ranking it in the top 43% of the BATSE fluence 
distribution. The average spectral hardness of the burst (H32), as 
determined by the ratio of total counts in the 100-300 keV to the 
50-100 keV range, is 0.811 (+/- 0.034), average for BATSE GRBs of 
this duration. The BATSE location error circle (90% conf.) is 
slightly offset (~2 degrees) from the BeppoSAX WFC location (GCN 393Not found
 
 
). 
The lightcurve and skymap location that includes the WFC and BATSE 
locations for this event (and other notable GRBs) are available at 
the BATSE Rapid Burst Response world-wide-web site:

          http://www.batse.msfc.nasa.gov/~kippen/batserbr/