POLARIS (α UMi),- MULTISTELLAR SYSTEM IN THE OPEN CLUSTER

Автор(и)

  • I. A. Usenko Department of Astronomy, Odessa National University T.G.Shevchenko Park, Odessa 65014 Ukraine, Ukraine
  • A. S. Miroshnichenko Dpt of Physics and Astronomy, University of North Carolina at Greensboro Greensboroo, NC 27402-6170, USA, United States
  • V. G. Klochkova Special Astrophysical Observatory, Russian Academy of Sciences Nizhnij Arkhyz, Karachaevo-Cherkessia, 369167 Russia, Russian Federation
  • V. E. Panchuk Special Astrophysical Observatory, Russian Academy of Sciences Nizhnij Arkhyz, Karachaevo-Cherkessia, 369167 Russia, Russian Federation

DOI:

https://doi.org/10.18524/1810-4215.2007.20.87212

Ключові слова:

Stars, abundances - Stars, distances - Stars, Cepheids - Stars, main-sequence stars - Stars, individual - &#945, UMi (Polaris A), Polaris B, HD 5914

Анотація

We present the results of our analysis of high-resolution spectroscopic observations of Cepheid α UMi (Polaris A) and main-sequence type stars Polaris B and HD 5914, - optical companion and a member of Polaris open cluster. The last ones are objects with high projected rotational velocities v sin i = 110 km s-1 and 100 km s-1, respectively. The derived atmosphere parameters are: Polaris A: Teff=6022 K; log g=2.2; Vt=4.3 km s-1; Polaris B: Teff=6900 K; log g=4.3; Vt=2.5 km s-1; HD 5914: Teff=8800 K; log g=4.0; Vt=2.0 km s-1. C, Na and Mg content in last two stars is close to solar, whereas Polaris A demonstrates its that is typical for Cepheid after the first dredge-up stage. The distances to Polaris B and HD 5914 are 109.5 and 108 pc, respectively. The RV pulsational amplitude of Polaris A decreased to 0.6 s-1 in 2005 and increased to 7.5 km s-1 in 2003

Посилання

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Опубліковано

2007-12-22

Номер

Том 20 № 1 (2007)

Розділ

Статті

Ліцензія

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