TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2588 SUBJECT: GRB040511 (=H3218): A Long GRB Localized by HETE WXM and SXC DATE: 04/05/11 17:07:56 GMT FROM: Roland Vanderspek at MIT GRB040511 (=H3218): A Long GRB Localized by HETE WXM and SXC A. Dullighan, 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, K. Torii, Y. Urata, T. Yamazaki, Y. Yamamoto, and A. Yoshida, on behalf of the HETE WXM Team; N. Butler, G. Crew, J. Doty, 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; M. Boer, J-F Olive, J-P Dezalay, C. Barraud, and K. Hurley, on behalf of the HETE FREGATE Team; report: At 13:01:46 UTC (46906 s UT) on 11 May 2004, the HETE FREGATE, WXM, and SXC instruments detected event GRB040511 (=H3218), a long, bright GRB. The burst triggered FREGATE in the 30-400 keV energy band. A flight localization was distributed automatically 39 minutes after the trigger: the long delay was due to dropouts in the HETE Burst Alert Network. Subsequent analysis of the full data set revealed that the prompt WXM Y location was in error: the correct WXM localization is a box with corners located at RA = 14h 47m 30.2s, Dec = -44d 15m 00s RA = 14h 48m 43.2s, Dec = -44d 11m 42s RA = 14h 49m 09.1s, Dec = -44d 41m 13s RA = 14h 47m 55.9s, Dec = -44d 44m 34s (J2000). Analysis of the SXC data reveal a 90% confidence error region of 80" radius (5.6 sq. arcmin area) centered at: SXC-Ground: RA = 14h 47m 50s, Dec = -44d 15' 04" (J2000). Preliminary analyses of the burst spectrum give a value of Epeak of ~100 keV and a 30-400 keV fluence of ~1e-5 erg/cm2, with a SNR of 32.2 and a duration (t90) of 38 s. Details of this burst can be found on the HETE web page at http://space.mit.edu/HETE/Bursts/GRB040511. This message can be cited.