Resolving X-ray sources from B-stars spectroscopically: The example of   mu Lep
  We present high-resolution X-ray observations of the chemically peculiar late-type B-star: mu Lep. However, we find spectroscopic and astrometric evidence, which show that the X-rays are not traced back to the B-star itself, but rather to a previously unresolved companion: mu Lep-B, whose X-ray spectrum resembles that of a coronally active source. We discuss the possibility that mu Lep-B is a pre-main-sequence companion, most likely of the non-accreting magnetically-active type. 
Ehud Behar, Maurice Leutenegger, Rami Doron, Manuel Guedel, Uri   Feldman, Marc Audard, and Steven M. Kahn