GCN Circular 1734

GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time

G. Crew, J. Villasenor, R. Vanderspek, J. Doty, G. Monnelly, N. Butler,
T. Cline, J.G. Jernigan, A. Levine, F. Martel, E. Morgan, G. Prigozhin,
G. Azzibrouck, J. Braga, R. Manchanda, and G. Pizzichini, on behalf of
the HETE Operations and HETE Optical-SXC Teams;

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

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

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

write:


At 11:18:34.03 UTC (40714.03 s UT) on 11 Dec 2002, the HETE FREGATE,
WXM, and SXC instruments detected event H2493, a bright, long GRB.  The
WXM flight localization was correct and was reported in a GCN Position
Notice at 11:18:56 UT, 22 sec after the beginning of the burst.

Ground analysis of the WXM data for the burst produced a refined
location, which was reported in a GCN Notice at 13:29:31 UT, 131
minutes after the burst.  The WXM localization SNR was  21.  The WXM
location can be expressed as a 90% confidence circle that is 5
arcminutes in radius and is centered at

RA = +08h 09m 04.8s, Dec = 06d 40'41" (J2000).

The uncertainty in the WXM localization is due entirely to systematic
error.

Ground analysis of the SXC data for the burst produced a further
refinement in the location, which was reported in the same GCN Notice
at 13:29:31 UT.  The SXC localization SNR was 23.  The SXC location can
be expressed as a 90% confidence circle that is 2 arcminutes in radius
and is centered at

RA = +8h 09m 00s, Dec = +06d 44' 20" (J2000).

The SXC localization may be improved.

The location of the optical afterglow candidate reported in GCN 1731
Not found
 
 

(D. W. Fox and P. A. Price) is offset by 3.2 arcmin from the center of
the WXM error circle and 42 arcsec from the center of the SXC error
circle. The location of the optical afterglow candidate is therefore
fully consistent with the WXM and SXC localizations for GRB021211.

The burst duration in the 8-40 keV band was > 5.7 sec. A total of 8310
counts were detected during that interval, corresponding to a fluence
of ~1 x 10-6 ergs cm-2 . The peak flux was >8 x 10-7 ergs cm-2 s-1
(i.e., > 20 x Crab flux) in 5msec.

A light curve and skymap for GRB021211 is provided at the following URL:

http://space.mit.edu/HETE/Bursts/

This message is citable.