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GCN Circular 2662

GRB040825B (=H3510): An XRF Localized in Real Time by HETE
2004-08-26T03:25:35Z (19 years ago)
Roland Vanderspek at MIT <>
GRB040825B (=H3510):  An XRF Localized in Real Time by HETE

Y. Urata, 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, T. Yamazaki, Y. Yamamoto, and A. Yoshida, on behalf of the

N. Butler, G. Crew, J. Doty, A. Dullighan, 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;

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


At 16:21:37 UTC (58897 s UT) on 25 August 2004, the HETE FREGATE and
WXM instruments detected event GRB040825B (=H3510), a long XRF.
The burst triggered the WXM in the 2-30 keV energy band;  the burst
duration is roughly 80 seconds.  

A flight localization was automatically forwarded to the GCN 31 seconds 
after the trigger.  The flight localization was a circle of 14' radius 
centered at 

  RA = 22h 47m 22s,   Dec = -02d 19' 05" (J2000)

Subsequent analysis of the full data set allowed the burst error region
to be reduced to a 160 sq. arcmin error box with the following coordinates, 
distributed by GCN Notice 1.8 hours after the trigger:

  RA = 22h 46m 38.9s, Dec = -02d 33m 40
  RA = 22h 46m 01.9s, Dec = -02d 29m 17s
  RA = 22h 46m 28.6s, Dec = -02d 15m 14s
  RA = 22h 47m 05.5s, Dec = -02d 19m 41s

Preliminary spectral analyses show the burst spectrum is well fit by
a cutoff powerlaw model with an Epeak of 23 keV.  The burst fluence
is 1.3e-6 erg/cm2 in the 2-30 keV band, 6.3e-7 erg/cm2 in the 30-400 
keV band;  GRB040825B is therefore an XRF.

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

Further observations of this source are encouraged.

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