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 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 ± 0.10 1.12 300x10 Rc 17.67 ± 0.04 3.75 300x9 Rc 18.53 ± 0.02 -------------------------------------------------