GCN Circular 4172

GRB 051028 (=H3951):  A GRB localized by HETE

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

M. Arimoto, T. Donaghy, E. Fenimore, M. Galassi, C. Graziani, 
N. Ishikawa, A. Kobayashi, J. Kotoku, M. Maetou, M. Matsuoka, 
Y. Nakagawa, T. Sakamoto, R. Sato, T. Shimokawabe, Y. Shirasaki, 
S. Sugita, M. Suzuki, T. Tamagawa, K. Tanaka, and A. Yoshida, on behalf 
of the HETE WXM Team; 

N. Butler, G. Crew, J. Doty, G. Prigozhin, R. Vanderspek, 
J. Villasenor, J. G. Jernigan, A. Levine, 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, and J-P Dezalay, on behalf of the HETE FREGATE 
Team; 

report:

At 13:36:01.47 UTC (48961.47 s UT) on 28 Oct 2005, the HETE FREGATE and
WXM instruments detected event H3951, a bright GRB.

The burst triggered FREGATE in the 30-400 keV energy band.  The burst
duration (T90) was 16 seconds in both the 30-400 keV band and the 
7-30 keV band.

Ground analysis of the WXM data produces a 90% confidence error region 
measuring 33 x 18 arcminutes with corners at the following coordinates:
  
    RA = 01h 50m 19.6s, Dec = +47d 41m 06s
    RA = 01h 47m 01.1s, Dec = +47d 38m 02s
    RA = 01h 46m 58.3s, Dec = +47d 55m 55s
    RA = 01h 50m 17.5s, Dec = +47d 58m 58s

The 30-400 keV fluence of GRB 051028 is 6e-6 erg/cm2; the 2-30 keV
fluences is 6e-7 erg/cm2.  The hardness ratio allows us to classify
this burst as a classical GRB.

Further information will be available at
  
  http://space.mit.edu/HETE/Bursts/GRB051028