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GCN Circular 2588

GRB040511 (=H3218): A Long GRB Localized by HETE WXM and SXC
2004-05-11T17:07:56Z (20 years ago)
Roland Vanderspek at MIT <>
GRB040511 (=H3218):  A Long GRB Localized by HETE WXM and SXC

A. Dullighan, G. Ricker, J-L. Atteia, N. Kawai, D. Lamb,
and S. Woosley, on behalf of the HETE Science Team;
T. Donaghy, E. Fenimore, M. Galassi, C. Graziani, M. Matsuoka,
Y. Nakagawa, T. Sakamoto, R. Sato, Y. Shirasaki, M. Suzuki,
T. Tamagawa, K. Torii, Y. Urata, T. Yamazaki, Y. Yamamoto,
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, J-P Dezalay, C. Barraud, and K. Hurley, on behalf
of the HETE FREGATE Team;


At 13:01:46 UTC (46906 s UT) on 11 May 2004, the HETE FREGATE, WXM, and 
SXC instruments detected event GRB040511 (=H3218), a long, bright GRB.

The burst triggered FREGATE in the 30-400 keV energy band.  A flight
localization was distributed automatically 39 minutes after the trigger:
the long delay was due to dropouts in the HETE Burst Alert Network.
Subsequent analysis of the full data set revealed that the prompt WXM
Y location was in error:  the correct WXM localization is a box with 
corners located at

  RA = 14h 47m 30.2s, Dec = -44d 15m 00s
  RA = 14h 48m 43.2s, Dec = -44d 11m 42s
  RA = 14h 49m 09.1s, Dec = -44d 41m 13s
  RA = 14h 47m 55.9s, Dec = -44d 44m 34s (J2000).

Analysis of the SXC data reveal a 90% confidence  error region of 
80" radius (5.6 sq. arcmin area) centered at:

  SXC-Ground:  RA = 14h 47m 50s, Dec = -44d 15' 04" (J2000).

Preliminary analyses of the burst spectrum give a value of Epeak of
~100 keV and a 30-400 keV fluence of ~1e-5 erg/cm2, with a SNR of 32.2 
and a duration (t90) of 38 s.

Details of this burst can be found on the HETE web page at

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