CXOM31 J004253.1+411422: the first ultraluminous X-ray transient in M 31 A. Kaur, M. Henze, F. Haberl, W. Pietsch, J. Greiner, A. Rau, D. H. Hartmann, G. Sala and M. Hernanz A&A, 538 (2012) A49 Published online: 31 January 2012 DOI: 10.1051/0004-6361/201118025