On the orbital and physical parameters of the HDE 226868/Cygnus X-1 binary system

  title={On the orbital and physical parameters of the HDE 226868/Cygnus X-1 binary system},
  author={Lorenzo Iorio},
  journal={Astrophysics and Space Science},
  • L. Iorio
  • Published 24 July 2007
  • Physics
  • Astrophysics and Space Science
In this paper we explore the consequences of the recent determination of the mass m=(8.7±0.8)M⊙ of Cygnus X-1, obtained from the Quasi-Periodic Oscillation (QPO)-photon index correlation scaling, on the orbital and physical properties of the binary system HDE 226868/Cygnus X-1. By using such a result and the latest spectroscopic optical data of the HDE 226868 supergiant star we get M=(24±5)M⊙ for its mass. It turns out that deviations from the third Kepler law significant at more than 1-sigma… 
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