IGR J17503–2636: a candidate supergiant fast X-ray transient C. Ferrigno, E. Bozzo, A. Sanna, G. K. Jaisawal, J. M. Girard, T. Di Salvo and L. Burderi A&A, 624 (2019) A142 Published online: 26 April 2019 DOI: 10.1051/0004-6361/201935185