TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1656 SUBJECT: IPN triangulation of GRB021025 (annulus) DATE: 02/10/26 01:37:30 GMT FROM: Kevin Hurley at UCBerkeley/SSL K. Hurley and T. Cline, on behalf of the Ulysses and HETE GRB teams, and G. Ricker, J-L Atteia, N. Kawai, D. Lamb, S. Woosley, J. Doty, R. Vanderspek, J. Villasenor, G. Crew, G. Monnelly, N. Butler, J.G. Jernigan, A. Levine, F. Martel, E. Morgan, G. Prigozhin, J. Braga, R. Manchanda, G. Pizzichini, Y. Shirasaki, C. Graziani, M. Matsuoka, T. Tamagawa, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, T. Tavenner, T. Donaghy, M. Boer, J-F Olive, and J-P Dezalay, on behalf of the HETE GRB team, report: Ulysses and HETE-FREGATE observed this burst at 73109 s. As observed by Ulysses, it had a duration ~10 s, a 25-100 keV fluence of ~1E-6 erg/cm2, and a peak flux over 0.25 s of ~5E-7 erg/cm2 s. We have triangulated it to a preliminary annulus centered at RA, Decl=178.652, +35.689 degrees, with radius 73.524 +/- 0.111 degrees (3 sigma). At this point it is not clear whether this event was observed by Mars Odyssey and thus whether an error box can be derived for it.