TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1253 SUBJECT: IPN/HETE Detection of Bursts from SGR1900+14 DATE: 02/02/19 21:48:24 GMT FROM: Kevin Hurley at UCBerkeley/SSL K. Hurley, on behalf of the Ulysses GRB team; G. Ricker, D. Lamb, S. Woosley, G. Crew, J. Doty, G. Monnelly, J. Villasenor, R. Vanderspek, N. Butler, J.G. Jernigan, A. Levine, F. Martel, E. Morgan, G. Prigozhin, J. Braga, R. Manchanda, G. Pizzichini, N. Kawai, M. Matsuoka, Y. Shirasaki, T. Tamagawa, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, T. Donaghy, C. Graziani, T. Tavenner, J-L Atteia, M. Boer, J-F Olive, and J-P Dezalay, on behalf of the HETE Team; M. Feroci, F. Frontera, C. Guidorzi, and E. Montanari, on behalf of the BeppoSAX GRBM team; and T. Cline, on behalf of the Ulysses and HETE GRB teams, report: A resurgence of activity from the soft gamma repeater SGR1900+14 has been detected by Ulysses and HETE-FREGATE, as evidenced by the detection of the following short bursts: Date Time at Time at Duration, Fluence, Ulysses HETE s. erg/cm^2 25-100 keV __________________________________________________________________ February 17 74060 s Not observed .032 10^-7 February 18 03916 s Not observed .032 4x10^-7 February 18 10143 s Not observed .12 2x10^-6 February 18 16661 s Not observed .25 10^-6 February 18 21936 s Not observed .22 1.4x10^-6 February 18 22632 s 23134 s .15 1.2x10^-4 Triangulation of the last event on February 18 gives an annulus consistent with the position of SGR1900+14. This SGR is presently ~130 degrees off-axis for FREGATE and the other HETE instruments. However, the last burst was ~100 times more intense than the preceding ones, which explains why it alone could have been detected through the collimator. Assuming that the other events were indeed from SGR1900 (because of their properties and proximity in time, any other origin is extremely unlikely), their Earth-crossing times would have been ~502 s later than the Ulysses times given above. Confirmation of the first five events is being searched for in the data of other spacecraft. (However, the BeppoSAX GRBM was not returning data for this period).