The Araucaria project. Bright variable stars in NGC 6822 from a wide-field imaging survey R. E. Mennickent, W. Gieren, I. Soszyński and G. Pietrzyński A&A, 450 2 (2006) 873-880 Published online: 10 April 2006 DOI: 10.1051/0004-6361:20054359