[vsnet-grb-info 18551] GRB 161001A: IRSF upper limits

[GCN Circulars]

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  <murata at u.phys.nagoya-u.ac.jp>

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.