GRB 130427A: Kanata/HOWPol optical imaging polarimetry. Itoh, R. ; Kawaguchi, K. ; Moritani, Y. ; Takaki, K. ; Kawabata, K. S. ; Ohno, M. ; Takahashi, H. ; Tanaka, Y. ; Yoshida, M. Abstract Publication: GRB Coordinates Network Pub Date: 2013 Bibcode: 2013GCN.14486....1I