TITLE: GCN CIRCULAR NUMBER: 16167 SUBJECT: GRB 140423A: Nishi-Harima NIR Observations DATE: 14/04/24 13:44:50 GMT FROM: Akira Arai at Nishi-Harima Astro. Obs/U of Hyogo J. Takahashi and A. Arai (Univ. of Hyogo) report on behalf of the Nayuta team and the OISTER collaboration: We observed the field of GRB 140423A (Sonbas et al., GCN 16142) with Nishiharima Infrared Camera (NIC) attached to the Nayuta 2-m telescope at the Nishi-Harima Astronomical Observatory. The observations were conducted on 2014-04-23 at 10:05-10:29 UT and 13:03-13:53 UT. We detected the near-infrared afterglow in H and Ks bands. Photometric results of our observations are listed below. We used 2MASS 13085994+4951082 as a reference star for photometry. # MID-UT Tmid-T0 T-EXP H_mag Ks_mag* ----------------------------------------------------------------------- 10:17:20 1.76 300 17.0 +/- 0.2 16.6 +/- 0.2 10:25:50 1.90 300 17.2 +/- 0.2 16.6 +/- 0.2 13:11:00 4.65 480 17.7 +/- 0.2 17.1 +/- 0.3 13:27:16 4.93 480 17.7 +/- 0.2 --** 13:44:50 5.22 600 17.7 +/- 0.2 17.3 +/- 0.3 ------------------------------------------------------------------------ Tmid-T0: Elapsed time after the burst (hours) T-EXP: Total Exposure time (seconds) * 2MASS Ks error for the reference star is not given, and thus it is not included in our error estimates for the GRB afterglow, ** Photometry was not possible.