Thermal-magnetic relation in a sunspot and a map of its Wilson depression S. K. Mathew, S. K. Solanki, A. Lagg, M. Collados, J. M. Borrero and S. Berdyugina A&A, 422 2 (2004) 693-701 Published online: 09 July 2004 DOI: 10.1051/0004-6361:20040136