The distance and size of the red hypergiant NML Cygni from VLBA and VLA astrometry

@article{Zhang2012TheDA,
  title={The distance and size of the red hypergiant NML Cygni from VLBA and VLA astrometry},
  author={B. Zhang and M. Reid and K. Menten and X. Zheng and A. Brunthaler},
  journal={Astronomy and Astrophysics},
  year={2012},
  volume={544}
}
Context. The red hypergiant NML Cyg has been assumed to be at part of the Cyg OB2 association, although its distance has never been measured directly. A reliable distance is crucial to study the properties of this prominent star. For example, its luminosity, and hence its position on the H-R diagram, is critical information to determine its evolutionary status. In addition, a detection of the radio photosphere would be complementary to other methods of determining the stellar size. 
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