GCN Circular 4932
E. Semkov (IA, BAS) on behalf of the BAS/CNRS collaboration report: We observed the afterglow of GRB 060218 (Cusumano et al., GCN 4775; Marshall et al., GCN 4800) with the 2m RCC telescope at the National Astronomical Observatory Rozhen (Bulgaria) on Mar. 21 and 26. The calibration was made using comparison stars from Hicken et al. (GCN 4898) and Modjaz et al. (astro-ph/0603377). Observations were made under good atmospheric conditions through a standard Johnson-Cousins set of filters. The optical counterpart was detected at the following magnitudes: Date, UT(R), I, R, V Mar 21 18:45 17.921 (0.062) 18.340 (0.027) 18.589 (0.026) Mar 26 18:00 18.106 (0.057) 18.429 (0.022) 18.916 (0.024) This message may be cited.