//////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1068 SUBJECT: SGR1806-20: Localization by HETE DATE: 01/06/18 21:45:45 GMT FROM: George Ricker at MIT SGR1806-20: Localization by HETE G. Ricker, D. Lamb, and S. Woosley on behalf of the HETE Science Team; R. Vanderspek, G. Crew, J. Doty, G. Monnelly, J. Villasenor; N. Butler, T. Cline, J.G. Jernigan, A. Levine, F. Martel, G. Pizzichini, and G. Prigozhin, on behalf of the HETE Operations and HETE Optical-SXC Teams; N. Kawai, M. Matsuoka, Y. Shirasaki, T. Tamagawa, A. Yoshida, E. Fenimore, M. Galassi, and C. Graziani, 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: At 19:42:49 UT on 18 June, the HETE FREGATE and WXM instruments detected and localized burst emission from the vicinity of SGR1806-20, a soft gamma-ray repeater. This event may indicate the onset of a new period of activity by this source. The coordinates (J2000) of the burst source were: R.A. = 272.0265 deg. Dec. = -20.2743 deg The error circle for the localization is 36 arcmin in radius. SGR1806-20 lies 11.8 arcmin from the HETE position. [Another galactic X-ray source, GX9+1, lies 100 arcmin from the HETE position.] The burst duration in the 8-40 keV band was <300 ms. A total of 864 counts were detected during that interval, corresponding to a flux of >10 times Crab. Follow-up observations of this transient are encouraged. Additional information on this burst detection (including light curves), as well as for the HETE mission, will be available at: http://space.mit.edu/HETE/ Acronyms: HETE=High Energy Transient Explorer FREGATE=French Gamma Ray Telescope WXM=Wide Field X-ray Monitor SXC=Soft X-ray Camera This message is citeable. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1070 SUBJECT: SGR1806-20: A Second, Intense Burst Localized by HETE DATE: 01/06/23 18:21:44 GMT FROM: George Ricker at MIT SGR1806-20: A Second, Intense Burst Localized by HETE G. Ricker, D. Lamb, and S. Woosley on behalf of the HETE Science Team; R. Vanderspek, G. Crew, J. Doty, G. Monnelly, J. Villasenor; N. Butler, T. Cline, J.G. Jernigan, A. Levine, F. Martel, E. Morgan, G. Pizzichini, and G. Prigozhin, on behalf of the HETE Operations and HETE Optical-SXC Teams; N. Kawai, M. Matsuoka, Y. Shirasaki, T. Tamagawa, K.Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, and C. Graziani, 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: At 15:54:53.123 UT on 23 June, the HETE FREGATE and WXM instruments detected and localized an intense burst from SGR1806-20, a soft gamma-ray repeater. This event, disseminated in near real time as a GCN Alert (HETE BID_1566; see http://gcn.gsfc.nasa.gov/gcn/hete_grbs.html), is the second burst localized from this source in the past week. (The first burst was reported in GCN Circular #1068). The coordinates (J2000) of the 23 June burst are: R.A. = 272.1460 deg. (18h08m35s.02) Dec. = -20.3658 deg. (-20:21:56) The error circle for this localization is 6 arcmin in radius. SGR1806-20 lies 3.1 arcmin from the HETE position. The burst duration in the 8-40 keV band was ~200 ms, comprised of two peaks each <100ms in duration. A total of 2250 counts were detected during that interval, corresponding to a fluence of ~4 x 10-7 ergs cm-2 . The peak flux was >6 x 10-6 ergs cm-2 s (ie >200 x Crab flux). Follow-up observations of this transient are encouraged. Additional information on this burst detection (including light curves), as well as for the HETE mission, will be available at: http://space.mit.edu/HETE/ Acronyms: HETE=High Energy Transient Explorer FREGATE=French Gamma Ray Telescope WXM=Wide Field X-ray Monitor SXC=Soft X-ray Camera This message is citeable. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1072 SUBJECT: Possible burst from SGR1806-20 DATE: 01/06/26 23:21:40 GMT FROM: Kevin Hurley at UCBerkeley/SSL K. Hurley, on behalf of the Ulysses GRB team, reports: In addition to observing the burst from SGR1806-20 on 2001 June 23 at 57293 s UT (GCN 1070), Ulysses observed a later event whose origin is likely to be this same SGR. This burst would have had an Earth-crossing time of 61056.8 s. Its duration was ~0.032 s, and its 25-100 keV fluence was ~2x10^-7 erg/cm^2. It had a peak flux over 0.032 s of ~6x10^-6 erg/cm^2 s. To our knowledge, no other instrument observed this event so we cannot be absolutely certain of its origin, but based on its time history and proximity in time to the previous burst, its origin is likely to be SGR1806-20, rather than SGR1900+14 (GCN 1071).