Nonazimuthal linear polarization in protoplanetary disks H. Canovas, F. Ménard, J. de Boer, C. Pinte, H. Avenhaus and M. R. Schreiber A&A, 582 (2015) L7 Published online: 09 October 2015 DOI: 10.1051/0004-6361/201527267