TITLE: GCN CIRCULAR NUMBER: 18439 SUBJECT: GRB 151022A: Kanata/HOWPol optical observation DATE: 15/10/22 15:10:33 GMT FROM: Koji Kawabata at HASC,Hiroshima U K. S. Kawabata, R. Itoh, T. Nakaoka, M. Yoshida (Hiroshima Univ.), K. Tsumura (Tohoku Univ.), and K. Arimatsu (NAOJ) report on behalf of Kanata team: We performed a series of optical imaging-polarimetry for the optical afterglow of GRB151022A (D'Avanzo et al., GCN 18436) from 119 sec after the Swift/BAT trigger with HOWPol attached to the 1.5-m Kanata telescope at Higashi-Hiroshima Observatory, Japan. We could not detect any afterglow within the XRT error circle reported in the GCN 18436. We obtained the following preliminary upper limits (3-sigma) in our first image (mid-time 134 sec after the trigger) calibrated with UCAC4: Rc > 17.0 Further analysis is ongoing.