1000 au exterior arcs connected to the protoplanetary disk around HL Tauri Hsi-Wei Yen, Shigehisa Takakuwa, You-Hua Chu, Naomi Hirano, Paul T. P. Ho, Kazuhiro D. Kanagawa, Chin-Fei Lee, Hauyu Baobab Liu, Sheng-Yuan Liu, Tomoaki Matsumoto et al. (6 more) A&A, 608 (2017) A134 Published online: 14 December 2017 DOI: 10.1051/0004-6361/201730894