TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  1530
SUBJECT: GRB020903(=H2314): An X-Ray Flash Localized by HETE
DATE:    02/09/03 17:12:01 GMT
FROM:    Don Lamb at U.Chicago  <lamb@oddjob.uchicago.edu>

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

R. Vanderspek, J. Doty, J. Villasenor, G. Crew, 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;

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

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

write:


At 10:05:37.96 UTC (36337.96 s UT) on 3 Sep 2002, the HETE WXM and SXC
instruments detected event H2314, an X-ray flash.  The WXM flight
localization was correct but was not set out as a GCN Notice because
events which trigger only the WXM are currently not sent out, in order
not to overwhelm the community with X-ray burst localizations.  Ground
analysis of the WXM data for the burst produced a refined location,
which was reported in a GCN Position Notice at 13:56:24 UT, 231 minutes
after the burst.  The WXM location can be expressed as a 90% confidence
circle that is 16.6 arcminutes in radius and is centered at

RA = 22h 49m 25s, Dec = -20o 53' 59" (J2000).


Ground analysis of the SXC data for the burst produced a
one-dimensional localization, which -- when combined with the WXM
localization -- produced a further refinement in the location.  This
refined location was reported in a GCN Position Notice at 17:00:34 UT,
7 hrs after the burst.  The refined location produced by combining the
SXC and WXM localizations can be expressed as a 90% confidence
quadrilateral that is 4 arcminutes in width and ~31 arcminutes in
length, is centered at


RA = 22h 49m 01s, Dec = -20o 55' 47" (J2000).

and is defined by

RA = 22h 48m 48.00  -20o 39' 36.0"
RA = 22h 48m 33.60  -20o 42' 36.0"
RA = 22h 49m 10.80  -21o 10' 12.0"
RA = 22h 49m 30.00  -21o 10' 48.0"


In the WXM 2-25 keV band, the burst had a duration of ~3.3 seconds.
The WXM localization SNR was ~10.  The SXC localization SNR was ~3.

Further information (including a light curve) for GRB020903 is provided
at the following URL:

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

This message is citable.