[vsnet-grb-info 20183] GRB 171222A: AROMA-N optical observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22279
SUBJECT: GRB 171222A: AROMA-N optical observation
DATE:    17/12/24 10:01:22 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto at phys.aoyama.ac.jp>

Y. Kitaoka, T. Sakamoto (AGU)

We observed the field of GRB 171222A detected by Swift (Racusin et al.
GCN circ. 22265) with the 0.3 m AROMA-N telescope located at
Aoyama Gakuin University (Sagamihara, Japan).  Due to the introduction
issue of the telescope, we only obtained one 120 sec image which contains
the location of the GRB.  The image was taken in the R filter starting from
December 12 on 18:53:26 (UT) about 140 minutes after the trigger and stopped
on 18:55:26 (UT).  We do not detect the optical afterglow in this image at
the location of the X-ray afterglow (Osborne et al. GCN circ. 22266).
The estimated five sigma upper limit is ~15.3 using the USNO-B1 catalog.