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arXiv · 1610.03813

Effective temperature and radial velocity of the small-amplitude Cepheid Polaris (alpha UMi) in 2015

I. A. Usenko·V. V. Kovtyukh·A. S. Miroshnichenko·S. Danford
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Abstract

We present the results of an analysis of 21 spectra of alpha UMi (Polaris) obtained in September - December 2015. Frequency analysis shows an increase of the pulsation period up to 8.6 min in comparison to the 2007 observational set. The radial velocity amplitude comes to 4.16 km s^-1, and it approximately twice the one found in 2007. The average Teff = 6017 K, and it is close to the value determined for the 2001-2004 set. Therefore Polaris moves to the red edge of the Cepheid instability strip (CIS)

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I. A. Usenko, V. V. Kovtyukh, A. S. Miroshnichenko, S. Danford. 2016-10-12. Effective temperature and radial velocity of the small-amplitude Cepheid Polaris (alpha UMi) in 2015. https://doi.org/10.18524/1810-4215.2016.29.85061

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