GCN Circular 12778
Subject
GRB111228A: Further GMG observations
Date
2011-12-30T04:04:44Z (12 years ago)
From
Xiao-hong Zhao at Yunnan Obs <zhaoxiaohong78@gmail.com>
X.-H. Zhao (YNAO), L. P. Xin (NAOC), J.-R. Mao (KASI/YNAO), J.-M. Bai
(YNAO) report on behalf of a larger collaboration:
We made a further observation of GRB 111228A (Ukwatta et al., GCN 12737) with 2.4m Gao-Mei-Gu (GMG) telescope. Observations
started at 16:07:37 UT on 2011-12-29 (i.e., ~24.4 hrs after the burst) . We found the afterglow has faded significantly. The magnitudes are as follows:
mid time (UT) Exp. (s) Filter magnitude (err)
2011-12-29 16:12:37 600 R 20.24 (0.12)
2011-12-29 16:27:55 600 V 20.67 (0.18)
2011-12-29 16:38:54 600 B 21.13 (0.15)
2011-12-29 16:52:46 600 R 20.33 (0.12)
2011-12-29 17:03:24 600 V 20.73 (0.18)
2011-12-29 17:14:06 600 B 21.31 (0.16)
2011-12-29 17:28:50 600 R 20.54 (0.13)
2011-12-29 17:39:39 600 V 20.96(0.21)
2011-12-29 17:51:19 600 B 21.40 (0.17)
The magnitudes were calibrated with the USNO-B1 #1083-0199833 star (R2 = 17.28 mag and (V-R)=+0.69; also
used by Klotz et al., GCN 12746; Nascimbeni et al., GCN 12748; Xu et
al., GCN 12750; Hentunen et al., GCN 12754; Klotz et al. GCN 12758).
We thank the GMG staff, especially Y.-X. Xin, Fen He, and Gui-Hua He for
performing these observations.