Faint open clusters with 2MASS: BH 63, Lyngå 2, Lyngå 12 and King 20 E. Bica, C. Bonatto and R. Blumberg A&A, 460 1 (2006) 83-92 Published online: 12 September 2006 DOI: 10.1051/0004-6361:20065443