TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1169 SUBJECT: GRB011130 (=XRF011130): Revised Localization of an X-ray DATE: 01/12/01 01:05:15 GMT FROM: George Ricker at MIT GRB011130 (=XRF011130): Revised Localization of an X-ray Flash/X-ray Rich GRB G. Ricker, D. Lamb, and S. Woosley on behalf of the HETE Science Team; N. Butler, G. Crew, J. Doty, G. Monnelly, G. Prigozhin, R. Vanderspek, J. Villasenor, T. Cline, J.G. Jernigan, A. Levine, F. Martel, E. Morgan, J. Braga, R. Manchanda, and G. Pizzichini, on behalf of the HETE Operations and HETE Optical-SXC Teams; C. Graziani, N. Kawai, M. Matsuoka, Y. Shirasaki, T. Tamagawa, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, T. Tavenner, and T. Donaghy, on behalf of the HETE WXM Team; J-L Atteia, M. Boer, J-F Olive, J-P Dezalay, and K. Hurley on behalf of the HETE FREGATE Team; write: The localization of H1764, an X-ray flash (XRF) reported as GRB011130 in GCN Circular 1165, has been greatly improved. The burst occurred at 22775.66 SOD (6:19:35 UT) on 30 November. Selection by hand of optimal background and foreground time intervals, and the optimal energy interval has resulted in a 19.6 sigma detection of GRB011130 in the WXM 2-10 keV energy band. The improved statistical error radius in the WXM localization is 7.2 arcmin (90% confidence). The spacecraft aspect has been improved to lie within a circle of 3.6 arcmin radius. The revised localization of H1864 is centered at: R.A. = 03h05m36s.45, Dec. = 3o48'37" A circle centered on this location having a radius 10 arcmin contains the burst location with > 90% confidence. The revised location differs significantly (~4 degrees) from the originally reported one; the contributing factors to the large difference are explained in detail in the "Special Note on Burst 1864" posted at: http://space.mit.edu/HETE/Bursts/ A careful re-analysis of the full WXM data set indicates that the burst is considerably longer, and of higher fluence, than reported in GCN1135. In the 2-10 keV band, the duration is ~30 s, with ~3100 counts contained in the burst. Further refinement of the spacecraft aspect, and thus the burst localization, continues. This message is quotable.