TITLE: GCN CIRCULAR NUMBER: 18656 SUBJECT: GRB 151127A iTelescope observation DATE: 15/12/02 13:35:18 GMT FROM: Takanori Sakamoto at AGU Y. Kitaoka, T. Sakamoto, A. Yoshida (AGU) We observed the field of GRB 151127A detected by Swift (trigger #665268; D'Ai et al., GCN Circ. 18643) with the iTelescope.Net (http://www.itelescope.net) T30 (20" Plane Wave) telescope located at the Siding Spring Observatory (New South Wales, Australia). 20 images of 60 sec exposures were taken in the R filter starting from November 27 09:47:56 (UT) about 39.1 minutes after the trigger and stopped on November 27 10:23:18 (UT). We do not detect the optical afterglow both in the individual images and the stacked image at the enhanced X-ray afterglow position (Goad et al., GCN Circ. 18647). The estimated five sigma upper limit of the combined image (total exposure of 1200 sec) is ~18.2 using the USNO-B1 catalog.