The peculiar X-ray source in NGC 5281

Recent observations with Chandra and XMM-Newton have shown that the X-ray source 1WGA J1346.5-6255 is associated with the Be star HD 119682, a member of the open cluster NGC 5281, and displays all the characteristics of the new class of X-ray sources known as γ-Cas analogues. We present a detailed spectroscopic study of this open cluster, finding an age of 40 Myr and a sequence of evolved stars. These results imply that HD 119682 is a blue straggler in NGC 5281, as it is much more massive than any other cluster member, and its membership is strongly suggested by proper motion analysis. This is the second γ-Cas analogue found to be blue straggler in an open cluster, suggesting that evolution plays a role in the formation of these systems and that a supernova explosion has not occurred in them.