TITLE: GCN CIRCULAR NUMBER: 16903 SUBJECT: GRB 141005A: iTelescope.Net T21 Optical Observation DATE: 14/10/07 12:57:06 GMT FROM: Takanori Sakamoto at AGU D. Kawamura, T. Sakamoto, A. Yoshida (AGU) We observed the field of GRB 141005A detected by Swift (trigger #614415; D'Elia et al., GCN Circ. 16882) with the iTelescope.Net (http://www.itelescope.net) T21 (0.43 m Planewave) telescope located at the New Mexico Skies Observatory (NM, USA). 60 images of 20 sec exposures and 20 images of 60 sec exposures were taken in the R filter starting from October 5 05:27:55 (UT) about 15 minutes after the trigger and stopped on October 5 06:33:49 (UT). We do not detect the optical afterglow both in the individual images and the stacked image at the enhanced X-ray afterglow position (Beardmore et al., GCN Circ. 16888). The estimated five sigma upper limit of the combined image (total exposure of 2400 sec) is ~18.4 using the USNO-B1 catalog.