Перегляд за Автор "Vasilyeva, S. V."

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  • Ескіз
    Документ
    About chemical composition of supergiant PMMR145 in Small Magellanic cloud. Osmium.
    (Astroprint, 2012) Gopka, Vera F.; Shavrina, Angelina V.; Vasilyeva, S. V.; Andrievsky, Serhii M.; Андрієвський, Сергій Михайлович; Андриевский, Сергей Михайлович
    ABSTRACT. The abundance analysis of six Ksupergiants of the Small Magellanic (Hill 1997) showed that the heavier elements (La, Ce, Nd, Eu) have the excess relative to iron [El/Fe]=+0.4 dex, on average, for the sample of five stars (PMMR23, PMMR27, PMMR48, PMMR102, PMMR145). We made the identification of spectral lines in the spectrum of PMMR145 based on the comparison of synthetic and observed spectra. The absorption lines of elements heavier than lanthanides including osmium were identified and abundance of osmium was found ([Os/Fe]=0.59 dex).
  • Ескіз
    Документ
    PRELIMINARY STUDY OF RED SUPERGIANT RM_1-667 IN THE LARGE MAGELLANIC CLOUD
    (Astroprint, 2012) Gopka, Vera F.; Shavrina, Angelina V.; Vasilyeva, S. V.; Yushchenko, A. V.; Yushchenko, V. A.
    The observed lines of hydrogen and another strong lines in the spectrum of RM_1-667 (red region of spectra, 5900-7100 Å, spectral type is K7 I) are discussed. Analysis of these lines indicates the presence of mass outflow from the star at a significant velocity. Using the iron lines and the model atmospheres of supergiants(Teff = 3750 K – 4300 K) of the Kurucz‘ grid, we obtained the iron abundance lg ε (Fe) = 6.75-7.08, which is equivalent to [Fe/H] equal -0.75 to -0.42.
  • Ескіз
    Документ
    The abundances of heavy elements in red supergiants of Magellanic Clouds
    (Astroprint, 2013) Gopka, Vera F.; Yushchenko, A. V.; Kovtyukh, Valery V.; Shavrina, Angelina V.; Yushchenko, V. A.; Vasilyeva, S. V.; Pavlenko, Y.; Andrievsky, Serhii M.; Андрієвський, Сергій Михайлович; Андриевский, Сергей Михайлович
    ABSTRACT. The spectra of Magellanic Clouds (MC) supergiants PMMR 23, PMMR 144 and RM 1- 667 with resolving power R=30,000 and signal to noise ratio near 100 obtained at 3.6 meter telescope in Chile were analysed. We present a report on the detailed investigation of MC supergiants, with spesial attention to the thorium abundance in these stars. The abundance patterns of three supergiants show that r-process elements are clearly detected in the atmospheres of investigated stars, but the abundances of s-processes elements can vary from star to star.