Stellar Rotation and the Extended Main-sequence Turnoff in the Open Cluster NGC 5822

  title={Stellar Rotation and the Extended Main-sequence Turnoff in the Open Cluster NGC 5822},
  author={Weijia Sun and Richard de Grijs and Licai Deng and Michael D. Albrow},
  journal={The Astrophysical Journal},
The origin of extended main-sequence turnoffs (eMSTOs) in intermediate-age (1–3 Gyr) clusters is one of the most intriguing questions in current star cluster research. Unlike the split main sequences found in some globular clusters, which are caused by bimodal populations in age and/or chemical abundances, eMSTOs are believed to be due to stellar rotation. We present a spectroscopic survey of MSTO stars in a nearby, intermediate-age (0.9 Gyr), low-mass (∼1.7 × 103 M⊙) Galactic open cluster, NGC… 

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