Long-lived, long-period radial velocity variations in Aldebaran: A planetary companion and stellar activity

@article{Hatzes2015LonglivedLR,
  title={Long-lived, long-period radial velocity variations in Aldebaran: A planetary companion and stellar activity},
  author={A. P. Hatzes and William D. Cochran and Michael Endl and E. W. Guenther and Phillip J. MacQueen and Michael Hartmann and Mathias Zechmeister and Inwoo Han and B.-C. Lee and G. A. H. Walker and S. Yang and Ana M. Larson and K.-M. Kim and David Mkrtichian and M. Doellinger and Attila E. Simon and L. Girardi},
  journal={arXiv: Solar and Stellar Astrophysics},
  year={2015}
}
We investigate the nature of the long-period radial velocity variations in Alpha Tau first reported over 20 years ago. We analyzed precise stellar radial velocity measurements for Alpha Tau spanning over 30 years. An examination of the Halpha and Ca II 8662 spectral lines, and Hipparcos photometry was also done to help discern the nature of the long-period radial velocity variations. Our radial velocity data show that the long-period, low amplitude radial velocity variations are long-lived and… 
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High-precision radial-velocity observations of the solar-type star 16 Cygni B (HR 7504, HD 186427), taken at McDonald Observatory and at Lick Observatory, have each independently discovered periodic
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