TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1262 SUBJECT: GRB020305 (=H1939): Localization of a GRB by HETE DATE: 02/03/06 18:45:56 GMT FROM: Don Lamb at U.Chicago GRB020305 (=H1939): Localization of a GRB by HETE G. Ricker, J-L Atteia, N. Kawai, D. Lamb, and S. Woosley on behalf of the HETE Science Team; J. Villasenor, R. Vanderspek, G. Crew, J. Doty, G. Monnelly, 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, P. Lestrade, and K. Hurley on behalf of the HETE FREGATE Team; write: At 11:55:25.05 UTC (42925.05 s UT) on 5 March 2002, the HETE FREGATE and WXM instruments detected a GRB. The burst, H1939, was promptly reported as a GCN Alert Notice within 42 seconds of the detection time. The main part of the burst began at 11:59:04 UTC (43144 s UT), just as the spacecraft reached the dawn terminator and the WXM high voltage was turning off. Accurate aspect was derived for H1939 from a full data set on the ground. Ground analysis produced a location which can be expressed as a circle with a 90% confidence radius of 25 arcminutes centered at RA = +12h 43m 03s, Dec = -14d 33' 06" (J2000) This location was reported in a GCN Alert Notice (issued at 5 Mar 2002 21:51:55 UT) GRB020305 (=H1939) has a duration in the FREGATE 32-400 keV band of T90 = 252 seconds. In the 8-40 keV FREGATE band, the peak flux in 3 s was approximately 7 x 10-8 ergs cm-2 s-1 (i.e., approximately 2.5 x Crab flux). No duration or peak flux can be derived in the 2-25 keV WXM band because only the first 12 seconds of the main (second) peak were observed by the WXM before high voltage turnoff. The statistical significance of the burst in the 2-25 keV WXM band in this 12-second interval was 5 sigma. Further information (including light curves) on GRB020305 is provided at the following URL: http://space.mit.edu/HETE/Bursts/ This message is citable.