TITLE: GCN CIRCULAR NUMBER: 22826 SUBJECT: GRB 180620A iTelescope observation DATE: 18/06/23 09:36:13 GMT FROM: Takanori Sakamoto at AGU M. Nakamura, T. Sakamoto (AGU) We observed the field of GRB 180620A detected by Swift (Evans et al., GCN Circ. 22798) with the iTelescope.Net (http://www.itelescope.net) T11 (Planewave 20") telescope located at the New Mexico Skies Observatory (NM, USA). 20 images of 60 sec exposures were taken in the R filter starting from June 20 on 10:11:01 (UT) about 1.6 hours after the trigger and stopped on 10:44:55 (UT). Due to the tracking issue of the telescope, we only obtained nine good quality images. We do not detect the optical afterglow both in the individual images and the stacked image at the UVOT position (Evans et al., GCN Circ. 22798). The estimated five sigma upper limit of the combined image (total exposure of 540 sec) is ~18.1 using the USNO-B1 catalog.