Measuring the magnetic field of a trans-equatorial loop system using coronal seismology D. M. Long, G. Valori, D. Pérez-Suárez, R. J. Morton and A. M. Vásquez A&A, 603 (2017) A101 Published online: 19 July 2017 DOI: 10.1051/0004-6361/201730413