TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2966 SUBJECT: GRB 050123(=H3666): A GRB Localized in Real Time by HETE DATE: 05/01/23 12:49:32 GMT FROM: Roland Vanderspek at MIT GRB 050123 (=H3666): A GRB Localized in Real Time by HETE K. Hurley, 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, Y. Urata, T. Yamazaki, Y. Yamamoto, and A. Yoshida, on behalf of the HETE WXM Team; R. Vanderspek, N. Butler, G. Crew, J. Doty, G. Prigozhin, 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, and J-P Dezalay, on behalf of the HETE FREGATE Team; report: HETE detected GRB 050123 at 10:22:54 (37374 s SOD) on 23 January 2005. GRB 050123 consists of a single peak of ~10 seconds duration and is clearly seen in both the 7-30 keV and 30-400 keV bands. The burst was localized in flight to coordinates RA = 10h 31m 33.5s, Dec = -11d 34m 15s (J2000) with a radius of 14'. The first flight localization was distributed 22 seconds after the burst trigger. Ground analyses of the burst allow us to refine the error box of GRB 050123 to a box with corners RA = 10h 31m 49.2s Dec = -11d 41m 31s (J2000) RA = 10h 30m 48.7s Dec = -11d 37m 01s RA = 10h 31m 23.2s Dec = -11d 15m 25s RA = 10h 32m 23.7s Dec = -11d 20m 02s Preliminary spectral analysis of the burst give a 30-400 keV fluence of 2e-6 erg/cm2 and an Epeak of 80 keV. Details of this burst may be found at http://space.mit.edu/HETE/Bursts/GRB050123 This message may be cited.