TITLE: GCN CIRCULAR NUMBER: 19999 SUBJECT: GRB 161001A: IRSF upper limits DATE: 16/10/06 04:48:24 GMT FROM: Katsuhiro L. Murata at Nagoya U K. L. Murata (Nagoya University), K. Miyakawa (Tokyo Institute of Technology), and T. Nagayama (Kagoshima University) We observed the field of GRB 161001A ( Page et al., GCN Circular #19967) with the near-infrared (J, H, Ks) simultaneous imaging camera SIRIUS attached to 1.4 m telescope IRSF ( InfraRed Survey Facility) in Sutherland observatory, South Africa. The observations started on 2016-10-01 02:41:46 UT (~ 95 min. after the burst). We could not detect the afterglow within the enhanced XRT error circle (Osborne et al., GCN Circular #19969) in the three bands. We have obtained the following preliminary upper limits (Vega magnitude system): J > 14.61 H >14.19 Ks > 14.01 Given magnitudes were calibrated against 2MASS point sources in this field. The upper limits were determined as the magnitudes of the fainter star within 1 arcmin from the enhanced XRT position. This observation was carried out by IRSF and OISTER collaboration.