TITLE: GCN CIRCULAR NUMBER: 12809 SUBJECT: GRB111228A :LOAO R-band Observations DATE: 12/01/06 02:50:13 GMT FROM: Yiseul Jeon at SNU/CEOU Minsung Jang, Myungshin Im, Yiseul Jeon (CEOU/Seoul National Univ.), and Yuji Urata (NCU) on behalf of a larger collaboration We continued our observation (Jeon et al. GCN 12791) of GRB 111228A (Ukwatta et al., GCN 12737) in R-band with a 1 m telescope at Mt. Lemmon, Arizona, US. Data were taken at 2011-12-31 UT and 2012-01-01 UT. For both of them, we detected the afterglow in stacked R-band images. We used a USNO B1 star near the afterglow, USNO-B1 1083-0199833 with R=17.28 following Klotz et al. (GCN 12746) for our photometry calibration, and current, rough estimates are given below. Mid-time [UT] | Mid-time[Since BAT] | Exptime [sec] | R-magnitude | ------------------------------------------------------------------------------------------------------------- 2011-12-31 08:40:25 | 64.92 hours | 300sec X 7 | 21.5 +/- 0.28 | 2012-01-01 11:19:52 | 91.58 hours | 300sec X 9 | 22.3 +/- 0.36 | We thank the LOAO operator, J. Yoon for his help with these observations.