TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1129 SUBJECT: Optical observation of SGR 1806-20 at the 6-m SAO telescope DATE: 01/11/03 19:18:24 GMT FROM: Alexei Pozanenko at IKI, Moscow G. Beskin, V. Debur, A. Panferov, I. Panferova, V. Plokhotnichenko (SAO), A. Pozanenko, (IKI), M. Boer, J.L. Atteia, A. Klotz (CESR/CNRS), G. Ricker (MIT) We have observed SGR 1806-20 during its probable gamma-ray activity (GCN 1068, 1089). Observations were performed with 6-meter telescope of Special Astrophysical Observatory equipped with the high time resolution Multichannel Panoramic Photometer-Polarimeter and MANIA registration system. Observations of a 1 arcmin diameter area covered IPN position of the object (K.Hurley, ApJ, 523, L37, 1999) were carried out in B band on June, 20th and August, 22nd. The start time on June, 20 is UT 19:58 (2 days after HETE trigger), and start time in August, 22 is UT 20:31 (16 hours after HETE trigger). Accumulation time is 4500s and 800s, respectively. The arrival time of each photon was measured with an accuracy of 1 mcsec, and the spatial resolution reached 0.2 arcsec. No variable emission in the range 2 mcsec - 1s was found in 300 sq.arcsec region centered in IPN source position. Three sigma upper limits for the relative power (in respect to background) of the variable radiation component in the form of triangle-like flares with a filling factor of 0.1 are: 35% at 5 mcsec, 10% at 0.5 ms, 5% at 0.01 s and 1% at 1s. Analysis of entire image area for variable emission is in progress.