First observations of magnetic holes deep within the coma of a comet F. Plaschke, T. Karlsson, C. Götz, C. Möstl, I. Richter, M. Volwerk, A. Eriksson, E. Behar and R. Goldstein A&A, 618 (2018) A114 Published online: 17 October 2018 DOI: 10.1051/0004-6361/201833300