TITLE:   GCN CIRCULAR
NUMBER:  14495
SUBJECT: GRB 130427A: Nishi-Harima NIR Observations
DATE:    13/04/29 00:11:01 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

J. Takahashi, K. Morihana, S. Honda and Y. Takagi (Univ. of Hyogo)
report on behalf of Nayuta team:

We observed the field of GRB 130427A (Masell et al., GCNC 14448)
in near-infared three bands (J, H and Ks) with NIC attached to the
Nayuta 2-m telescope at the Nishi-Harima Astronomical Observatory.

The observations were conducted from 2013-04-27 12:26 UT to 2013-04-27
17:25 UT (from ~4.7 h to ~9.6 h after the burst).
We detected the previously reported afterglow (Elenin et al., GCNC 14450)
in all the three bands.

Photometric results of our observations are listed below.
We used 2MASS 11323755+2743196 as the reference star for flux calibration.

# MID-UT   T-EXP[sec]  J    J_err H    H_err  Ks    Ks_err
-----------------------------------------------------------------------
12:26:56     150       14.7  0.2  13.5  0.2   13.5   0.2
13:27:59     150       14.7  0.2  14.2  0.2   13.2   0.3
14:39:42     150       14.7  0.3  14.3  0.2   13.4   0.3
17:17:31     150       --*   --*  14.8  0.2   14.6   0.2
17:24:52     300       15.2  0.2  14.8  0.2   14.0   0.2
------------------------------------------------------------------------
T-EXP: Total Exposure time [sec]
* Photometry was not possible because the signal from the reference star
was too low.