GCN Circular 22250
Y. Kitaoka, T. Sakamoto (AGU) We observed the field of GRB 171211A detected by Swift (Gropp et al., GCN Circ. 22234) with the iTelescope.Net (http://www.itelescope.net) T27 (Planewave 27") telescope located at the AstroCamp Observatory (Siding Spring Observatory, AU). 8 images of 60 sec exposures were taken in the I filter starting from December 11 on 11:41:37 (UT) about 134 minutes after the trigger and stopped on 11:54:45 (UT). We do not detect the optical afterglow both in the individual images and the stacked image at the X-ray afterglow position. The estimated five sigma upper limit of the combined image (total exposure of 480 sec) is ~17.2 using the USNO-B1 catalog.