TITLE: GCN CIRCULAR NUMBER: 18746 SUBJECT: GRB 151228A: T60 observations DATE: 15/12/29 07:59:13 GMT FROM: Eda Sonbas at NASA/GSFC Sonbas, E. (Adiyaman Univ.), Parmaksizoglu, M. (TUG), Guver, T. (Istanbul Univ.), Gogus, E. (Sabanci Univ.), Dindar, M., Kirbiyik, H. (TUG) on behalf of a larger collaboration. We observed the field of GRB 151228A (Ukwatta et al., GCN #18731) with the 0.60 meter T60 telescope (TUBITAK National Observatory, Antalya - Turkey), starting on December 28, 03:06:43.45 UT (~ 90 sec after the trigger). We obtained 3 x 60 s + 2 x 20 s exposures with R filters under good weather conditions. We do not detect an optical afterglow within the reported BAT error circle down to a limiting magnitude of >~17 (2-sigma) in the combined R band image. We thank to TUBITAK National Observatory for a partial support in using T60 telescope with project number 13DT60-539 and technical support.