TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1220 SUBJECT: GRB020124(=H1896): Localization of a Long GRB by HETE DATE: 02/01/24 23:54:57 GMT FROM: George Ricker at MIT GRB020124(=H1896): Localization of a Long GRB by HETE G. Ricker, J-L Atteia, N. Kawai, D. Lamb, and S. Woosley on behalf of the HETE Science Team; G. Crew, R. Vanderspek, J. Doty, G. Monnelly, J. Villasenor, N. Butler, T. Cline, J.G. Jernigan, A. Levine, F. Martel, E. Morgan, G. Prigozhin, J. Braga, R. Manchanda, and G. Pizzichini, on behalf of the HETE Operations and HETE Optical-SXC Teams; M. Matsuoka, Y. Shirasaki, T. Tamagawa, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, T. Tavenner, T. Donaghy, and C. Graziani, on behalf of the HETE WXM Team; M. Boer, J-F Olive, J-P Dezalay, and K. Hurley on behalf of the HETE FREGATE Team; write: At 10:41:15.15 UTC (38475.15 s UT) on 24 January, the HETE FREGATE and WXM instruments detected and localized a long GRB. The burst, H1896, was promptly reported as a GCN Alert Notice within 11 seconds of the detection time, but no flight localization was derived. In a followup GCN Notice issued 1.4 hours after the GRB, the results of an initial ground analysis localization were reported as an error box with dimensions of 26 arcmin x 27 arcmin. Further ground analysis of the WXM data has produced a significantly improved location which can be expressed as a circle with a 90% confidence radius of 12 arc minutes centered at: RA = +09h 32m 49s, Dec = -11d 27' 35" (J2000) The revised error circle reported here is displaced by 9.2 arc minutes from the best-fit location found in the initial HETE ground analysis and reported in a GCN Notice (at 24 Jan 2002 12:06:53 UT). The burst duration in the FREGATE 8-85 keV band was ~70 s. A total of 12,870 counts were detected during that interval, corresponding to a fluence of ~3 x 10-6 ergs cm-2 . The peak flux over 0.164s was >1 x 10-7 ergs cm-2 s-1 (i.e., >3 x Crab flux). The statistical significance was 9 sigma in the WXM 2-25 keV band. This message is quotable.