TITLE: GCN CIRCULAR NUMBER: 12773 SUBJECT: GRB 111228A: Liverpool Telescope Observations DATE: 11/12/29 21:14:20 GMT FROM: Carole Mundell at ARI, JMU,Liverpool A. Melandri (INAF-OAB), C. Guidorzi (U. Ferrara), C. G. Mundell (Liverpool JMU) and N. R. Tanvir (U. Leicester), on behalf of a large collaboration report: "We observed the optical afterglow of GRB 111228A (Ukwatta et al., GCN 12737) with the 2-m Liverpool Telescope, starting at 02:55 UT on 2011 December 29. We took a sequence of images in Br'i' bands, with exposure time of 300s for each individual frame. We clearly detect the optical afterglow in all individual images. In stacked frames we find the following magnitudes for the OT: Mid time from Total Exp Filter Magnitude trigger (hr) (s) -------------------------------------------------- 12.08 4x300 r' 19.68 +- 0.06 13.28 3x300 r' 19.89 +- 0.09 12.54 5x300 i' 19.57 +- 0.05 11.34 4x300 B 19.71 +- 0.08 12.96 4x300 B 19.79 +- 0.11 -------------------------------------------------- The magnitudes are calibrated against nearby SDSS-5 (r' and i' bands) and USNO-B1.0 (B band) field stars and are not corrected for the Galactic extinction. This message may be cited."