TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2706 SUBJECT: An intense burst from SGR1806-20 DATE: 04/09/13 11:41:23 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks on behalf of Konus-Wind and Helicon/Coronas-F teams, T. Cline on behalf of the Konus-Wind team, and A. Rau, A. von Kienlin, G. Lichti on behalf of the INTEGRAL SPI-ACS GRB team report: An intense SGR-like burst was detected by Konus-Wind on September 10 at 35441.919 s (09:50:41.919) UT and Helicon-Coronas-F at 35438.674 s (09:50.38.674) UT. We have triangulated it to an annulus centered at RA(2000) = 325.353 deg, Decl(2000) = -13.289 deg, whose radius is 51.241 +/- 0.156 deg (3 sigma). This burst was also observed by Integral SPI-ACS. The Konus-Wind - INTEGRAL triangulation annulus is: RA(2000) = 322.942 deg, Decl(2000) = -8.645 deg, Radius = 50.227 +/- 0.328 degrees (3 sigma). These annuli intersect to form two error boxes, one of which may be eliminated by the Konus ecliptic latitude response. The remaining error box includes the position of SGR 1806-20, so we believe that it is the source of this event. Additionaly, two SGR-like bursts were detected recently by Konus-Wind. The Konus ecliptic latitude response indicates that the source of these bursts is near ecliptic plane, so we suppose, that they are also originated from SGR 1806-20. The following table summarizes the bursts (as observed by Konus-Wind): Date Time*, Duration, Fluence, Peak Flux, s UT s (20-200 keV) (20-200 keV) ergs/cm2 ergs/cm2 s ----------------------------------------------------------------------- 040830 23313.143 0.14 2.4E-6 3.6E-5 040908 45466.575 0.33 8.3E-6 5.0E-5 040910 35441.919 0.58 1.7E-5 4.6E-5 ------------------------------------------------------------------------