A search for new variable stars in NGC 6231 T. Arentoft, C. Sterken, M. R. Knudsen, L. M. Freyhammer, H. W. Duerbeck, E. Pompei, C. E. Delahodde and J. W. Clasen A&A, 380 2 (2001) 599-608 Published online: 15 December 2001 DOI: 10.1051/0004-6361:20011472