First detection of a diamagnetic cavity at comet 67P/Churyumov-Gerasimenko C. Goetz, C. Koenders, I. Richter, K. Altwegg, J. Burch, C. Carr, E. Cupido, A. Eriksson, C. Güttler, P. Henri et al. (9 more) A&A, 588 (2016) A24 Published online: 11 March 2016 DOI: 10.1051/0004-6361/201527728