TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5426 SUBJECT: GRB060806 is similar to previous activity of SGR1806-20 DATE: 06/08/09 10:21:45 GMT FROM: Dmitry Frederiks at Ioffe Institute S.Golenetskii, D.Frederiks, V.Pal'shin, R.Aptekar, T.Cline and E.Mazets on behalf of the Konus-Wind team report: The soft gamma-ray event 060806 related to SGR1806-20 (Hurley et al., GCN 5416, 5419) is of great interest, However it hardly can be defined as unique for SGR1806-20, all of the main features of this event were also observed earlier. In 2006 SGR1806-20 renewed its activity in the middle of July. Until now it has emitted about 20 soft bursts. Date UT, s Instrument/Spacecraft Konus-Wind Konus-A (Cosmos-2421) 060717 50457 yes yes 060717 57178 yes no 060718 11636 yes no 640718 64171 no yes 060718 69585 yes yes 060721 61862 yes no 060728 30102 no yes 060729 76209 yes no 060731 27269 yes yes 060806 21037 yes yes 060806 51824 yes no 060807 3806 yes no 060807 5881 yes yes 060807 34982 yes no 060807 83305 yes no 060808 16377 yes no The GRB060806 composes a cluster of 6 separate bursts similar to clusters observed in 2004 on October 5, December 24 and 25. Energy spectra of all bursts in the table are identical, revealing the same value of kT = 20 +/- 0.5 keV. What is more, the last burst in the cluster, wich lasts for ~30 s and exhibits three broad pulses separated by time intervals of ~7.55 s, strikingly resembles the light curve of the soft burst from SGR 1806-20 occured on December 3, 2005. This burst also starts a quick growing spike followed by a long tail with two broad if less pronounced peaks of periodic pulsations. Date Duration Fluence Fmax kT sec erg cm-2 erg cm-2 s-1 keV 060806 30.8 2.4x10-4 4.7x10-5 20 051203 22 1.6x10-4 3.4x10-5 20 A comparative chart of the two events lightcurves one can find at: http://www.ioffe.ru/LEA/SGR/060806/0806-060806-051203.jpg