STELLAR INVESTIGATION IN THE OPEN CLUSTER OF POLARIS

Автор(и)

  • I. A. Usenko Department of Astronomy, Odessa National University T.G.Shevchenko Park, Odessa 65014 Ukraine, Ukraine
  • A. S. Miroshnichenko Ritter Observatory, University of Toledo Toledo, OH 43606 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/10.18524/1810-4215.2008.21.86879

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, an 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 -1, respectively. The derived atmosphere parameters are: Polaris A: Teff=6020 K; log g=2.2; Vt=4.2 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 for Polaris A these values are 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 increased to 7.5 km s-1 in 2003, decreased to 0.6 km s-1 in 2005 and increased anew to 2.5 s-1 in 2007.

Посилання

Arellano Ferro A.: 1984, MNRAS, 209, 481.

Bessel M.S., Castelli F., Pfelz B.: 1998, A&A, 333, 231.

ESA 1997, The Hipparcos and Tycho catalogues, ESA-SP 1200.

Evans N.R., Sasselov D.D., Short C.I.: 2002, ApJ, 567, 1121.

Evans N.R., Schaefer G., Bond H.E. et al.: 2007, Proceed. IAU Symp. No.240 (in press).

Fernie J.D.: 1966, AJ, 71, 731.

Galazutdinov G.A.: 1992, Preprint SAO RAS, No.92.

Gray D.: 1992, Observation and Analysis of Stellar Atmospheres, (Cambrige Univ. Press, 2nd ed.)

Kamper K.W.: 1996, JRASC, 90, 140.

Kovtyukh V.V., Gorlova N.I.: 2000, A&A 358, 587.

Nordgren T.E., Germain M.E., Benson J.A. et al.: 1999, AJ, 118, 3032.

Straizys V.: 1982, ”Metal-Deficient Stars”, Vilnius, ”Mosklas”, 300.

Turner D.G.: 2005, OAP, 18, 115.

Turner D.G., Usenko I.A., Miroshnichenko A.S., Klochkova V.G., Panchuk V.E.: 2006, AAS, 208, 4401.

Usenko I.A., Miroshnichemnko A.S., Klochkova V.G., Yushkin, M.V.: 2005, MNRAS, 362, 1219.

##submission.downloads##

Опубліковано

2008-12-21

Номер

Розділ

Статті