Coronal emission from the shocked circumstellar ring of SN 1987A P. Gröningsson, C. Fransson, P. Lundqvist, T. Nymark, N. Lundqvist, R. Chevalier, B. Leibundgut and J. Spyromilio A&A, 456 2 (2006) 581-589 Published online: 31 August 2006 DOI: 10.1051/0004-6361:20065325