%0 Journal Article %T Swift J053041.9-665426, a new Be/X-ray binary pulsar in the Large Magellanic Cloud %A G. Vasilopoulos %A P. Maggi %A F. Haberl %A R. Sturm %A W. Pietsch %A E. S. Bartlett %A M. J. Coe %J Physics %D 2013 %I arXiv %R 10.1051/0004-6361/201322335 %X We observed the newly discovered X-ray source Swift J053041.9-665426 in the X-ray and optical regime to confirm its proposed nature as a high mass X-ray binary. We obtained XMM-Newton and Swift X-ray data, along with optical observations with the ESO Faint Object Spectrograph, to investigate the spectral and temporal characteristics of Swift J053041.9-665426. The XMM-Newton data show coherent X-ray pulsations with a period of 28.77521(10) s (1 sigma). The X-ray spectrum can be modelled by an absorbed power law with photon index within the range 0.76 to 0.87. The addition of a black body component increases the quality of the fit but also leads to strong dependences of the photon index, black-body temperature and absorption column density. We identified the only optical counterpart within the error circle of XMM-Newton at an angular distance of ~0.8 arcsec, which is 2MASS J05304215-6654303. We performed optical spectroscopy from which we classify the companion as a B0-1.5Ve star. The X-ray pulsations and long-term variability, as well as the properties of the optical counterpart, confirm that Swift J053041.9-665426 is a new Be/X-ray binary pulsar in the Large Magellanic Cloud. %U http://arxiv.org/abs/1309.0736v1