TITLE: GCN CIRCULAR NUMBER: 4131 SUBJECT: GRB051022 (=H3590), A GRB Detected By HETE DATE: 05/10/22 14:55:35 GMT FROM: Carlo Graziani at U.Chicago J-F Olive, G. Ricker, J-L. Atteia, N. Kawai, D. Lamb, and S. Woosley, on behalf of the HETE Science Team; M. Arimoto, T. Donaghy, E. Fenimore, M. Galassi, C. Graziani, N. Ishikawa, A. Kobayashi, J. Kotoku, M. Maetou, M. Matsuoka, Y. Nakagawa, T. Sakamoto, R. Sato, T. Shimokawabe, Y. Shirasaki, S. Sugita, M. Suzuki, T. Tamagawa, K. Tanaka, 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-P Dezalay, and K. Hurley, on behalf of the HETE FREGATE Team; report: HETE Fregate, WXM, and SXC detected GRB 051022(=H3590) at 13:07:58 on 22 October 2005. The messages sent from the satellite in real time indicate that the burst is both valid and unusually bright. Because of a dropout of the internet connection to our ground station at Cayenne, additional no data were downlinked at the last contact: if this dropout persists, we will not have complete spectral and temporal data from GRB051022 until 19h UT. The HETE team believes that the coordinates distributed in real time are correct, and we urge that followup observations of these coordinates be made. The localization distributed in real time from the WXM was RA = 23h 55m 53s, Dec = +19d 37' 43" (J2000) with a 90% confidence error region of 14' radius. The localization distributed in real time from the SXC was RA = 23h 56m 00s, DEC = +19d 35' 51" (J2000) with a 90% confidence error radius of 2.5 arcminutes. Since the SXC coordinates cannot be independently verified until after the full data set is downlinked, we urge imaging of the full WXM error region. [GCN OPS NOTE(22oct05): Per author's request, the author list was added.]