Перегляд за Автор "Belik, S. I."

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    HQ CAR IS A NEW W VIR TYPE STAR
    (Astroprint, 2013) Udovichenko, S. N.; Kovtyukh, Valery V.; Egorova, I. A.; Belik, S. I.
    HQ Car is listed as an Cep star (DCEP) in the GCVS. High-resolution spectra of HQ Car showed the presence of the Balmer and He I 5876˚A emissions. The light curve shows steeper rise than decline, and there is evidence for the presence of a bump in the descending branch around the phase of 0.4. From considerations of the period, spectral type, presence of the bump, Helium and Balmer emissions we conclude that HQ Car belongs to the W Vir class of Type II Cepheids.
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    n-CAPTURE ELEMENTAL ABUNDANCES IN ACTIVE AND NON-ACTIVE STARS
    (Astroprint, 2010-07) Basak, N. Yu.; Mishenina, T. V.; Soubiran, C.; Kovtyukh, Valery V.; Belik, S. I.
    Abundances of Y, Zr, La, Ce, Nd, and Sm have been obtained under LTE approximationss. The program stars were observed at high resolution, high signal to noise ratio with the ELODIE echelle spectrograph (OHP, France). Among them more than 30 stars are active stars with a fraction of BY Dra and RS CVn type stars. Comparison of the behavior of n-capture elemental abundance in active and non active stars was made.
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    Spectroscopical study of faint Southern Cepheids with Southern African Large Telescope (SALT). First results.
    (Одеський національний університет імені І. І. Мечникова, 2017) Usenko, I. A.; Kniazev, A. Yu.; Kovtyukh, Valery V.; Belik, S. I.; Berdnikov, L. N.
    First Cepheids observations using echelle-spectrograph HRS fed by Southern African Large Telescope (SALT) were realized during 2016. All spectra have been obtained in the medium resoltion mode (R 31000–41000) wth high S/N ratio near 50–220. All data were processed using package developed by authors based on the standard system of astronomical data reduction MIDAS. Using new echelle data we found the atmosphere parameters and chemical composition for 30 faint Cepheids of southern hemisphere, where for the most of theses stars these results we obtained for the first time. 28 stars are Cepheids after the first-dredge up stage, while ASAS 075842-25336.1 and ASAS 1131714-6605.0 having remarkable Li I 6707.8 ˚A absorption line and anomalous CNO and Na content could be consider as first crossing of the Cepheids instability strip.
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    THE STUDY OF GALACTIC BEAT CEPHEIDS WITH APPLICATION OF ITS RESULTS TO THOSE IN THE MAGELLANIC CLOUDS
    (Astroprint, 2014) Chekhonadskikh, F. A.; Kovtyukh, Valery V.; Belik, S. I.
    A thorough study of the correlation between P1=P0 ratio, fundamental period, and chemical composition (abundances of metals that compose Z) was conducted to investigate the significance of the iron-peak elements on the ratio. The results suggested a more accurate P1=P0 ratio that can be useful as an alternative means of determining a beat Cepheid’s metallicity. Metallicities for a large sample of stars were analysed using the suggested ratio. The metallicity distribution function for the Magellanic Clouds projected on the celestial sphere was constructed for the first time, and several stars with anomalous metallicities were detected. The average metallicities of the Magellanic Clouds were also obtained independently: –0.30 dex for the Large Magellanic Cloud (LMC) and –0.49 dex for the Small Magellanic Cloud (SMC). The [Fe=H] values for two newly-found bimodal Cepheids in the Galactic bulge were estimated: –0.39 dex for OGLE-BLG-CEP-03 and –0.29 dex for OGLE-BLG-CEP-21.