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GCN Circular 2429

GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
2003-10-26T22:21:11Z (21 years ago)
George Ricker at MIT <>
GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE

N. Butler, G. Ricker, J-L. Atteia, N. Kawai, D. Lamb, and S. Woosley 
on behalf of the HETE Science Team;

T. Donaghy, C. Graziani, E. Fenimore, M. Galassi, M. Matsuoka, T. 
Sakamoto, Y. Shirasaki, M. Suzuki, T. Tamagawa, K. Torii, A. Yoshida, 
Y. Nakagawa, R. Satoh, Y. Urata, T. Yamazaki and Y. Yamamoto, on 
behalf of the HETE WXM Team;

G. Crew, J. Doty, A. Dullighan, G. Prigozhin, R. Vanderspek, J. 
Villasenor, J. G. Jernigan, G. Azzibrouck, J. Braga, R. Manchanda, 
and G. Pizzichini, on behalf of the HETE Operations and HETE 
Optical-SXC Teams;

M. Boer, J-F Olive, J-P Dezalay, C. Barraud, and K. Hurley on behalf 
of the HETE FREGATE Team;


At 05:35:43.25 UTC (20143.25 s UT) on 26 October 2003, the HETE 
FREGATE and WXM instruments detected event H2882, a faint, long-hard 

The burst triggered FREGATE in the 25-400 keV energy band.  Ground 
analysis of the WXM data provided a localization that was reported in 
a GCN Notice at 08:51:20 UT, 3.26 hours after the burst. The  WXM 
ground localization SNR was 6. The WXM localization can be expressed 
as a 90% confidence circle, with a radius of 15 arcminutes, centered 

WXM-Ground:  R.A. = +03h 18m 42s, Dec. = +28d 21' 58" (J2000).

An automated fit of a cutoff power-law spectrum has been performed 
for H2882.  The fit of the model to the data is posted at

 From the automated fit, the calculated values of Epeak and the burst 
fluence (25-100 keV) posted at the above website are:
--Epeak    	= 330 keV
--Fluence  	= 2.3e-06 erg/cm^2
--Duration(t90) 	= 114.2 seconds

Also posted at the above website are the following data, in the 
formats described by Vanderspek (GCN 2421):
--Fregate light curve and ascii data tables (energy bands A[7-30 
keV], B[7-80 keV], and C[30-400 keV])
--Color-color plot location of H2882 relative to other HETE-localized bursts
--Signal-to-noise histogram location of H2882 in Fregate Band C 
relative to other HETE-localized bursts

We note that the counts ratio (Band_B/Band_A > 1.8) for H2882 is one 
of the most extreme values yet measured by HETE.

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