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GCN Circular 442

GRB 991105: BATSE Observations
1999-11-08T23:18:20Z (25 years ago)
R. Marc Kippen at BATSE/UAH/MSFC <>
R. M. Kippen, S. Phengshamnan & T. Giblin (University of Alabama in
Huntsville) report on behalf of the BATSE GRB team:

GRB 991105 was detected by BATSE on 1999 November 5.694963 UT as
trigger number 7841.  The event consisted of a complex series of
pulses with two major episodes and significant spectral evolution.
The T50 and T90 durations are 12.35 (-/+ 1.90) s and 48.64 (-/+ 1.36)
s, respectively.  The burst's peak flux (50-300 keV; integrated over
1.024 s) and fluence (>20 keV) are 1.98 (-/+ 0.06) photons cmE-2 sE-1
and 4.01 (-/+ 0.79) x 10E-6 erg cmE-2, respectively---ranking it in
the top 20% (38%) of the BATSE burst flux (fluence) distribution.  The
average spectral hardness of the burst, as estimated by the ratio of
100-300 keV counts to those in the 50-100 keV range, is H32 = 0.83
(-/+ 0.01), which is average for bursts of this duration.  The BATSE
burst location is consistent with those measured by BeppoSAX (GCN 430)
and the IPN (SAX/NEAR; GCN 411).  The lightcurve for this event will
be available shortly at: http://gammaray/batse/grb/lightcurve/
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