EFFECTIVE TEMPERATURE AND RADIAL VELOCITY OF THE SMALL AMPLITUDE CEPHEID POLARIS (alpha UMi) IN 2015

Автор(и)

  • I. A. Usenko Astronomical Observatory, Odessa National University, Ukraine
  • V. V. Kovtyukh Astronomical Observatory, Odessa National University, Ukraine
  • A. S. Miroshnichenko Dept. of Physics and Astronomy, University of North Carolina at Greensboro, United States
  • S. Danford Dept. of Physics and Astronomy, University of North Carolina at Greensboro, United States

DOI:

https://doi.org/10.18524/1810-4215.2016.29.85061

Ключові слова:

Stars, radial velocities, Cepheids, overtone pulsations, alpha Umi

Анотація

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 kms-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).

Посилання

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Опубліковано

2016-12-01

Номер

Розділ

Астрофізика (зоряні атмосфери, взаємодіючі подвійні системи, змінні зорі)