TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2480 SUBJECT: IPN/HETE localization of GRB031203B (=H2949; large error box) DATE: 03/12/06 16:34:24 GMT FROM: Kevin Hurley at UCBerkeley/SSL K. Hurley and T. Cline, on behalf of the HETE and Konus-Wind GRB teams, G. Ricker, J-L Atteia, N. Kawai, D. Lamb, S. Woosley, J. Doty, R. Vanderspek, J. Villasenor, G. Crew, G. Monnelly, N. Butler, J.G. Jernigan, A. Levine, F. Martel, E. Morgan, G. Prigozhin, J. Braga, R. Manchanda, G. Pizzichini, Y. Shirasaki, C. Graziani, M. Matsuoka, T. Tamagawa, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, T. Tavenner, T. Donaghy, M. Boer, J-F Olive, and J-P Dezalay, on behalf of the HETE GRB team, and E. Mazets and S. Golenetskii, on behalf of the Konus-Wind GRB team, report: Konus-Wind and HETE (FREGATE and WXM) observed this GRB at 21537 seconds. Its duration was approximately 9 seconds. We have triangulated it to a preliminary annulus centered at RA, Decl(2000)= 76.207, 18.592 degrees, with radius 56.016 +/- 1.739 degrees (3 sigma). GRB031203B was detected by HETE as trigger H2949. The burst was detected just a few seconds before the end of orbital science operations, when the optical aspect was not available. It was observed by the WXM X-camera, but not by the Y camera. This event has a hard spectrum (Epeak ~ 160 keV) and a 30-400 keV fluence of 8E-6 erg/cm2. The HETE localization is a circle of 10 degree radius centered at RA, Decl(2000)=133.41, +53.22 degrees. The IPN annulus intersects this circle at four points to form an error box whose area is approximately 69 sq. degrees. The intersection points are: RA(2000) DEC(2000) 134.252 43.235 123.689 61.775 130.660 63.116 138.978 43.915 A map has been posted at ssl.berkeley.edu/ipn3/031203B. HETE lightcurves and the results of automated spectral analyses can be found on the HETE web page http://space.mit.edu/HETE/Bursts/GRB031203b. This localization may be improved, but a small error box cannot be determined for this event.