TITLE: GCN CIRCULAR NUMBER: 18121 SUBJECT: GRB 150811A: KAIT optical candidate DATE: 15/08/11 05:06:41 GMT FROM: Weikang Zheng at UC Berkeley WeiKang Zheng (UC Berkeley), Xianggao Wang (UC Berkeley, GXU, UNLV) and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to Swift GRB 150811A (Evans et al., GCN 18119) about 10 minutes after the burst. Observations were performed with an automatic sequence in the clear (roughly R), V, and I filters, and the exposure time was 20 s per image. Inside the XRT error circle we detected an un-cataloged source with coordinates of : RA = 19:25:21.40 (J2000) DEC= -15:25:30.96 (J2000) The object has I band mag of ~16.5 at ~15 minutes after burst and is decaying. We suggest this is the afterglow of GRB 150811A. Follow-up observations are encouraged.