GCN Circular 12791
Subject
GRB 111228A: LOAO Optical Observation
Date
2011-12-31T11:58:29Z (13 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
Yiseul Jeon, Myungshin Im, Minsung Jang (CEOU/Seoul National
Univ.), and Yuji Urata (NCU) on behalf of a larger collaboration
We observed GRB 111228A (Ukwatta et al., GCN 12737) in
B- and R-bands with a 1 m telescope at Mt. Lemmon, Arizona, US.
The observation started at 2011-12-30 08:03:16 UT,
or 1.7 days after the BAT aleart. We detected the afterglow
in the images taken with both filters.
Using the the photometry calibration based on an USNO B1 star
USNO-B1 1083-0199833 with B=18.85 and R=17.28 following Klotz et al.
(GCN 12746), we find the following.
Filter Mid-Time[UT] Mid-Time[Since BAT] Mag
B-band 2011-12-30 08:33:55 40.82 hours 21.75+-0.14
R-band 2011-12-30 10:41:29 42.95 hours 20.67+-0.09
Further observation is ongoing. We thank the LOAO operator,
J. Yoon for his help with the observation.