Probing the Faintest Stars in a Globular Star Cluster

@article{Richer2006ProbingTF,
  title={Probing the Faintest Stars in a Globular Star Cluster},
  author={Harvey B. Richer and Jay Anderson and James P. Brewer and Saul D. Davis and Gregory G. Fahlman and Brad Hansen and Jarrod Hurley and Jason S. Kalirai and Ivan R. King and David Brian Reitzel and Robert Michael Rich and Michael M. Shara and Peter B. Stetson},
  journal={Science},
  year={2006},
  volume={313},
  pages={936 - 940}
}
NGC 6397 is the second closest globular star cluster to the Sun. Using 5 days of time on the Hubble Space Telescope, we have constructed an ultradeep color-magnitude diagram for this cluster. We see a clear truncation in each of its two major stellar sequences. Faint red main-sequence stars run out well above our observational limit and near to the theoretical prediction for the lowest mass stars capable of stable hydrogen burning in their cores. We also see a truncation in the number counts of… 

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  • J. Kalirai
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    Proceedings of the International Astronomical Union
  • 2008
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