TITLE: GCN CIRCULAR NUMBER: 17425 SUBJECT: GRB 150203A iTelescope observation DATE: 15/02/07 11:36:49 GMT FROM: Takanori Sakamoto at AGU D. Kawamura, T. Sakamoto, A. Yoshida (AGU) We observed the field of GRB 150203A detected by Swift (trigger #629578; Ukwatta et al., GCN Circ. 17377) with the iTelescope.Net (http://www.itelescope.net) T11 (0.50 m Plane Wave) telescope located at the New Mexico Skies Observatory (NM, USA). 20 images of 60 sec exposures were taken in the R filter starting from February 3 4:22:11 (UT) about 13.3 minutes after the trigger and stopped on February 3 4:47:29 (UT). We do not detect the optical afterglow both in the individual images and the stacked image at the enhanced X-ray afterglow position (Evans et al., GCN Circ. 17378). The estimated five sigma upper limit of the combined image (total exposure of 1200 sec) is ~18.9 using the USNO-B1 catalog.