Evolutionary status of Polaris

@article{Fadeyev2015EvolutionarySO,
  title={Evolutionary status of Polaris},
  author={Yu. A. Fadeyev},
  journal={Monthly Notices of the Royal Astronomical Society},
  year={2015},
  volume={449},
  pages={1011-1017}
}
  • Yu. A. Fadeyev
  • Published 23 February 2015
  • Physics
  • Monthly Notices of the Royal Astronomical Society
Hydrodynamic models of short--period Cepheids were computed to determine the pulsation period as a function of evolutionary time during the first and third crossings of the instability strip. The equations of radiation hydrodynamics and turbulent convection for radial stellar pulsations were solved with the initial conditions obtained from the evolutionary models of population I stars (X=0.7, Z=0.02) with masses from 5.2 to 6.5 Msol and the convective core overshooting parameter 0.1 <= aov <= 0… 

Figures and Tables from this paper

Evolution, pulsation and period change in the Cepheid SZ Tau
The study is devoted to radial pulsations in Population I Cepheids with masses from 5.4M⊙ to 6 M⊙. Solution of the equations of radiation hydrodynamics and turbulent convection for nonlinear stellar
A Model of the Mira–Type Star T UMi
Stellar evolution calculations were carried out from the main sequence to the final stage of the asymptotic giant branch for stars with initial masses 1 M⊙ ≤ MZAMS ≤ 2 M⊙ and metallicity Z = 0.01.
Evolutionary and Hydrodynamic Models of Short-Period Cepheids
The evolutionary calculations for population I stars with masses on the main sequence 5 M_\odot 5.1M_\odot. The grid of hydrodynamic models of core helium--burning Cepheids on the stages of the
Evolution and Period Change in RR Lyr Variables of the Globular Cluster M 3
The grid of evolutionary tracks of population II stars with initial masses 0.81 M⊙ ≤ MZAMS ≤ 0.85 M⊙ and chemical composition of the globular cluster M3 is computed. Selected models of horizontal
Evolutionary Status and Fundamental Parameters of the Cepheid V1033 Cyg
On the basis of consistent stellar evolution and nonlinear stellar pulsation calculations the Cepheid V1033 Cyg is shown to be the post--main sequence star at the first crossing of the instability
Evolution and Pulsations of Population I Post-AGB Stars
Evolutionary calculations of population I stars with initial masses $M_0=1M_\odot$, $1.5M_\odot$ and $2M_\odot$ were carried out up to the stage of the proto--planetary nebula. Selected models of
Homing in on Polaris: A 7 M⊙ first-overtone Cepheid entering the instability strip for the first time
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
Evolving pulsation of the slowly rotating magnetic β Cep star ξ1 CMa
Recent BRITE-Constellation space photometry of the slowly rotating, magnetic β Cep pulsator ξ1 CMa permits a new analysis of its pulsation properties. Analysis of the two-colour BRITE data reveals
The shape of convective core overshooting from gravity-mode period spacings
Context. The evolution of stars born with a convective core is highly dependent on the efficiency and extent of near core mixing processes, which effectively increases both the core mass and
On Period Distribution of RR Lyr Type Variables in the Globular Cluster M3
Evolutionary calculations of population II stars with chemical composition of the globular cluster M3 were carried out under various assumptions about the initial stellar mass ($0.809M_\odot\le
...
...

References

SHOWING 1-10 OF 39 REFERENCES
Theoretical rates of pulsation period change in the Galactic Cepheids
Theoretical estimates of the rates of radial pulsation period change in Galactic Cepheids with initial masses 5.5 M⊙ ≤ MZAMS ≤ 13 M⊙, chemical composition X = 0.7, Z = 0.02 and periods 1.5 day ≤ Π ≤
Evolution and pulsation period change in the Large Magellanic Cloud Cepheids
Theoretical estimates of the pulsation period change rates in LMC Cepheids are obtained from consistent calculation of stellar evolution and nonlinear stellar pulsation for stars with initial
On the Pulsation Mode Identification of Short-Period Galactic Cepheids
We present new theoretical period-radius relations for first-overtone Galactic Cepheids. Current predictions are based on several sequences of nonlinear, convective pulsation models at solar chemical
The Period Changes of Polaris
The evolutionary changes in pulsation period for the Cepheid Polaris are reinvestigated using archival observational material (radial velocities, photometry, and eye observations) over the interval
Instability of LBV stars against radial oscillations
Hydrodynamic calculations of nonlinear radial oscillations of LBV stars with effective temperatures 1.5 × 104 K ⩽ Teff ⩽ 3 × 104 K and luminosities 1.2 × 106L⊙ ⩽ L ⩽ 1.9 × 106L⊙ have been performed.
Instability of radial modes at the Wolf-Rayet evolutionary stage
AbstractThe evolution of a Population-I star with an initial mass MZAMS = 60 M⊙ has been calculated. At the stage when a red giant turns into an early-type helium star, the vast bulk of the stellar
The radial-velocity variations of Polaris - A Cepheid leaving the instability strip
The radial velocities of Cepheid Polaris are measured using 237 Reticon spectra. The data show a pulsation period of 3.9746 + or - 0.0008 days and RV amplitude 2K = 1.50 + or - 0.08 km/s. It is shown
THE PERIOD CHANGE OF THE CEPHEID POLARIS SUGGESTS ENHANCED MASS LOSS
Polaris is one of the most observed stars in the night sky, with recorded observations spanning more than 200 years. From these observations, one can study the real-time evolution of Polaris via the
The Pulsation Mode of the Cepheid Polaris
A previously derived photometric parallax of 10.10  ±  0.20 mas, d = 99  ±  2 pc, is confirmed for Polaris by a spectroscopic parallax derived using line ratios in high dispersion spectra for the
PRECISE RADIAL VELOCITIES OF POLARIS: DETECTION OF AMPLITUDE GROWTH
We present the first results of a long-term program of a radial velocity (RV) study of Cepheid Polaris (F7 Ib), with the aim of finding the amplitude and period of its pulsations and the nature of
...
...