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 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.