TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1641 SUBJECT: GRB021016(=H2397): A Long GRB Localized by HETE DATE: 02/10/17 02:53:08 GMT FROM: Don Lamb at U.Chicago C. Graziani, Y. Shirasaki, M. Matsuoka, T. Tamagawa, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, T. Tavenner, and T. Donaghy, on behalf of the HETE WXM Team; G. Ricker, J-L Atteia, N. Kawai, D. Lamb, and S. Woosley on behalf of the HETE Science Team; J. Villasenor, R. Vanderspek, J. Doty, G. Crew, G. Monnelly, N. Butler, T. Cline, J.G. Jernigan, A. Levine, F. Martel, E. Morgan, G. Prigozhin, 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; write: At 10:29:00.75 UTC (37740.75 s UT) on 16 Oct 2002, the HETE FREGATE and WXM instruments detected event H2397, a long GRB. The burst occurred inside the FREGATE FOV, but at 35 degrees off the WXM boresight and illuminated only two of the twelve wires of the WXM. Ground analysis of the WXM data for the burst produced a location in the X-direction from the shadow pattern of the coded aperture mask on these two wires, and a location in the Y-direction from geometrical constraints. A final WXM location was reported in a GCN Notice at 20:18:15 UT. The WXM localization SNR in the X-detector was 6. The WXM location can be expressed as a 90% confidence rectangle that is approximately 14 arcminutes in width and 11 degrees in length. The corners of the rectangle lie at the following J2000 coordinates: RA = 00h 38m 35s, Dec = 45o 57' 47" RA = 23h 43m 26s, Dec = 52o 18' 43" RA = 23h 42m 46s, Dec = 52o 07' 30" RA = 00h 39m 30s, Dec = 46o 09' 18". GCN Circulars No. 1639 and 1640 reported a combined HETE/Ulysses IPN diamond-shaped localization region that has an area of approximately 200 sq. arcminutes. In the FREGATE 8-40 keV and the WXM 2-25 keV bands, the burst had a duration of ~90 seconds. A light curve and skymap for GRB021016 are provided at the following URL: http://space.mit.edu/HETE/Bursts/ This message is citable.