TITLE: GCN CIRCULAR NUMBER: 10385 SUBJECT: GRB 100206A, RIMOTS optical upper limits DATE: 10/02/06 22:03:16 GMT FROM: Kazuhiro Noda at Miyazaki U K.Noda, E.Sonoda, H.hayasi, K.Kono, N.Ohmori, A.Daikyuji, Y.Nisioka, M.Yamauchi (University of Miyazaki) We have observed the field covering the error circle of GRB GRB090206A (Swift trigger 411412, GCN 10376, Krimm et al.) with the unfiltered CCD camera on the 30-cm telescope at University of Miyazaki. The observation was started 13:31:14 UT, about 1 min after the Swift trigger time. We have compared our data of 30 sec exposures with the USNO-A2.0 catalog, There is no new source at the reported position. the upper limits are as follows: -------------------------------------------------------------- Start(UT) End(UT) Num. of frames Limit (mag.) -------------------------------------------------------------- 13:31:14 13:31:44 1 14.1 13:31:14 14:26:55 29 17.4 ---------------------------------------------------------------