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

I. A. Usenko, A. S. Miroshnichenko, V. G. Klochkova, V. E. Panchuk

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

Ключові слова


Stars; abundances - Stars; distances - Stars; Cepheids - Stars; main-sequence stars - Stars; individual - α UMi (Polaris A); Polaris B; HD 5914

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Посилання


Arellano F erro A.: 1984, MNRAS, 209, 481.

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

ESA, 1997: The Hipparc os and Tycho c atalogues, 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 Atmospher es, (Cambrige Univ. Press, 2nd e dition).

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

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

Nordgren T.E. et al.: 1999, AJ, 118, 3032.

Panchuk V.E., Najdenov I.D., Klochkova V.G. et al.: 1998, Bull. SAO RAS 44, 127.

Panchuk V.E., Klochkova V.G., Najdenov I.D. et al.: 1999, Preprint SAO RAS, No. 139.

Panchuk V.E., Piskunov N.E., Klochkova V.G., Yushkin M.V., Ermakov S.V.: 2002, Preprint SAO RAS, No. 169.

Roemer E.: 1965, ApJ, 141, 1415.

Straiˇ zys 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., Yang S.L.S, Gregory P .C.: 2006, BAAS, 38, 118.

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

Usenko I.A., Miroshnichemnko A.S., Klochkova V.G., Panchuk V.E.: 2005a, OAP, 18, 130.




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

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