TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4278 SUBJECT: GRB 051028 Optical Observations DATE: 05/11/16 15:03:15 GMT FROM: T.P. Prabhu at Indian Astro. Obs. D.K. Sahu, S. Srividya and S. Vanniarajan (Indian Institute of Astrophysics, Bangalore,India) communicate on behalf of a larger Indian collaboration: We observed the central 10x10 arcmin region of the error circle of the HETE trigger 3951 in Bessell R and I filters with the 2-m Himalayan Chandra Telescope, Hanle, India, starting from 16:15 UT, 2005 October 28 (about 2.7 hours after the burst). We could clearly detect the OT of GRB 051028 reported by Jelinek et al. (GCN 4175). The preliminary R band magnitude for the OT, estimated using the calibration provided by Henden (GCN 4184), is R=20.77+/-0.10 at 16:18 UT. The OT decayed by ~1.3 mag in R band in 1.5 hours. Further analysis is in progress. This message may be cited.