TITLE: GCN CIRCULAR NUMBER: 3782 SUBJECT: Detection of an intermediate burst from SGR 1806-20 on August 8 DATE: 05/08/10 14:42:12 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks on behalf of Konus-Wind and Helicon/Coronas-F teams, and T. Cline on behalf of the Konus-Wind team report: A SGR-like burst 050808 triggered Konus-Wind at 67438.919 s UT (18:43:58.919). It was also detected by Helicon-Coronas-F in the waiting mode. We have triangulated it to a wide annulus centered at RA(2000) = 302.888 deg, Decl(2000) = -22.871 deg, whose radius is 31.070 � 3.188 deg (3 sigma). As the center line of this annulus passes 2.46 degrees (2.3 sigma) from the position of SGR 1806-20 and the Konus ecliptic latitude response indicates that the source of the burst is near ecliptic plane, we believe that this burst originated from SGR 1806-20. The burst had a duration of ~1.1 sec, fluence (6.9 � 0.2)10-6 erg/cm2, and peak flux on 64-ms time scale (1.2 � 0.3)10-5 erg/cm2 s (both in 20-200 keV range). The burst light curve demonstartes nearly linear decline during ~1 s (the burst rise was missed by Konus-Wind; the total burst duration was estimated combining the K-W background and trigger data). The time-integrated spectrum of the burst can be fitted by the OTTB spectral model: dN/dE ~ E^{-1} exp(-E/kT), with kT = 18.5 � 0.8 keV.