The Lorentz force in atmospheres of chemically peculiar stars: 56 Arietis D. Shulyak, O. Kochukhov, G. Valyavin, B.-C. Lee, G. Galazutdinov, K.-M. Kim, I. Han and T. Burlakova A&A, 509 (2010) A28 Published online: 14 January 2010 DOI: 10.1051/0004-6361/200912615