TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4137 SUBJECT: GRB 051022 (=H3950): SXC Flight Localization is Valid DATE: 05/10/22 17:33:30 GMT FROM: George Ricker at MIT GRB 051022 (=H3950): SXC Flight Localization is Valid K. Tanaka, 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, 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, and K. Hurley, on behalf of the HETE FREGATE Team; report: The HETE team, after reviewing the the real-time messages from HETE regarding GRB 051022(=H3950), believes that the SXC real-time localization of this burst is valid. As reported in GCN Notices beginning 118 seconds after the initial trigger and in GCN Circular 4131, the SXC real-time localization can be described as a circle centered at RA = 23h 56m 00s, DEC = +19d 35' 51" (J2000) with a 90% confidence error radius of 2.5 arcminutes. This SXC localization corresponds not only to the highest correlation peak in the WXM error circle, but also to the highest correlation peak in the entire SXC field-of-view. Therefore GRB 051022 was sufficiently bright in soft X-rays that the SXC position was determined independently of the WXM result. In addition, there is good reason to believe that the duration of GRB 051022 is > 2-4 minutes and that there are periods of low emission during the X-ray prompt emission. These indications, combined with the upper limit of R > 20 by Cenko et al (GCN 4134), suggest that searches at NIR and infrared wavelengths for a high redshift object in the SXC error region would be of interest.