[vsnet-grb-info 11375] GRB 111228A: Optical and NIR observations with Kanata telescope

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  12787
SUBJECT: GRB 111228A: Optical and NIR observations with Kanata telescope
DATE:    11/12/31 01:04:46 GMT
FROM:    Michitoshi Yoshida at HASC,Hiroshima U  <yoshidam at hiroshima-u.ac.jp>

R. Itoh, K. Takaki, M. Yamanaka, M. Sasada, K. Sakimoto, M. Yoshida,
K. S. Kawabata, Y. Hanabata, M. Ohno, Y. Fukazawa (HiroshimaUniv.),
A. Nakashima (Tokyo Univ.) report on behalf of the Kanata collaboration:

We performed optical and near infrared observations of GRB 111228A
(Ukwatta et al., GCN 12737; Xin et al., GCN 12738) with the 1.5 m Kanata
Telescope of Higashi-Hiroshima observatory, Japan. The observation
started at 15:47 UT on 2011 December 28. We took a sequence of images
in Rc and K bands, and detected the optical-infrared afterglow of the
GRB (Veli-Pekka Hentunen et al. GCN 12754; Kuroda et al. GCN 12743;
Nicuesa Guelbenzu et al. GCN 12757; Usui et al. GCN 12768).

Photometric results are listed below. We used USNO-B1 catalog for flux
calibration of Rc band, and 2-MASS catalog for Ks band.

Mid time from  Total Exp   Filter    Magnitude
trigger (hr)    (s)
-------------------------------------------------
0.34            180x5        Ks    14.94 $B!^(B 0.10
1.12            300x10       Rc    17.67 $B!^(B 0.04
3.75            300x9        Rc    18.53 $B!^(B 0.02
-------------------------------------------------