X-ray flares in Orion low-mass stars M. Caramazza, E. Flaccomio, G. Micela, F. Reale, S. J. Wolk and E. D. Feigelson A&A, 471 2 (2007) 645-654 Published online: 18 June 2007 DOI: 10.1051/0004-6361:20077195