GCN Circular 5648
G. Kornienko, A. Erofeeva (UAPhO), A.Pozanenko (IKI), V.Rumyantsev (CrAO) on behalf of larger GRB follow up collaboration report: We observed the error box of GRB060923C (Stamatikos et al., GCN 5591) with 0.4m telescope of Ussuriysk Astrophysical Observatory in R-band starting Sep.23 (UT) 13:51:55. We do not detect the optical transient detected by Fox (GCN 5607). Upper limits of the first image (exposure 60 s) and combined image (exp. 10x60 s) are based on USNOA2.0: Mid time, Exposure, Limiting mag (3 sigma) (UT) (s) Sep. 23.5781 1x60 16.0 Sep. 23.5829 10x60 17.3 This message may be cited.