Homing in on Polaris: A 7 M⊙ first-overtone Cepheid entering the instability strip for the first time

  title={Homing in on Polaris: A 7 M⊙ first-overtone Cepheid entering the instability strip for the first time},
  author={Richard I. Anderson},
  journal={Astronomy and Astrophysics},
  • R. Anderson
  • Published 1 March 2018
  • Physics
  • Astronomy and Astrophysics
A recently presented HST/FGS parallax measurement of the Polaris system has been interpreted as evidence for the Cepheid Polaris Aa to be pulsating in the second overtone. An age discrepancy between components A and B has been noted and discussed in terms of a stellar merger. Here I show that the new parallax of Polaris is consistent with a simpler interpretation of Polaris as a $7 \rm{M}_\odot,$ first-overtone, classical Cepheid near the hot boundary of the first instability strip crossing… 

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