Zeta Pup: the merger of at least two massive stars
  We first discuss the stellar and wind parameters of zeta Pup resulting from detailed UV diagnostics. These parameters together with the runaway nature of the star can most easily be explained by dynamical binary-binary or binary-single star interactions in dense stellar clusters. In this case zeta Pup is most likely the merger of at least two massive stars. 
Dany Vanbeveren
astro-ph.GA