TITLE:   GCN CIRCULAR
NUMBER:  23165
SUBJECT: GRB 180821A: iTelescope counterpart is not the afterglow
DATE:    18/08/22 10:06:54 GMT
FROM:    Albert Kong at NTHU  <akhkong@gmail.com>

A. K. H. Kong (NTHU, Taiwan) reports

We reanalyse the image obtained with the T30 telescope of
iTelescope.Net (Kong GCN 23160) together with the enhanced Swift XRT
position (Evans et al. GCN 23162). Within the new error circle, we do
not detect any source with a detection limit of ~20.5 mag. The result
is consistent with Guidorzi et al. (GCN 23163). We conclude that the
previous counterpart candidate (which is outside the enhanced X-ray
error circle) is not the optical afterglow.