GCN Circular 2712

GRB040916 (= H3558):  A Long XRF Localized by HETE

T. Yamazaki, 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, Y. Urata, Y. Yamamoto, and A. Yoshida, on behalf of the 
HETE WXM Team; 

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; 

report:

At 00:03:30 UT (209 SOD) on 16 September 2004, the WXM instrument
on HETE detected GRB040916 (= H3558), a long, two-peaked XRF.  The 
burst has been localized to a circle of 18' radius centered on

  RA = 23h 01m 44s, Dec = -5d 37' 43" (J2000)

The burst consists of two peaks separated by ~250s, each ~100s in 
duration.  No formal spectral analysis has been performed using WXM
data, but the dearth of counts in bands > 10 keV in either peak is a 
strong indication that GRB040916 is an XRF.

We anticipate providing additional spectral information from this 
unusual event in a subsequent GCN Circular.

This message may be cited.