Udovichenko S.N., Keir L.E. «Photometry and Blazhko effect in RR Lyr-type star AE Leo» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 140-142 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114381 The photometric observations for the RR Lyr-type star AE Leo in the Astronomical station near Odessa using the 48-cm reflector AZT-3 and the CCD photometer equipped with the V filter have been carried out. The light curves shows variable amplitude of light maxima and the moderate Blazhko effect. The analysis of the O–C light maxima for our observations and the ASAS, NSVS data indicates the secular period changes.

Usenko I.A., Kniazev A.Yu., Kovtyukh V.V., Belik S.I., Berdnikov L.N. «Spectroscopical study of faint southern Cepheids with Southern African large telescope (SALT). first results» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 143-145 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.117156 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) with 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.

Usenko I.A., Kovtyukh V.V., Miroshnichenko A.S., Danford S. «Pulsational activity of the small-amplitude Cepheid Polaris (α UMi) in 2016–2017» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 146-148 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114382 We present the results of an analysis of 49 spectra of α UMi (Polaris) obtained during August–December 2016 and January–March 2017. Frequency analysis displays an unexpected decrease of the pulsational period up to 17.3min in comparison to the 2015 observational set. The radial velocity amplitude was reduced to 3.43 km s^–1 in 2016 and to 3.31km s^–1 in the beginning of 2017 in comparison with 4.16 km s^–1 in 2015. This result is also unexpected, because during the last decade a gradual amplitude growth has been observed. The average T_eff=6021 K determined from the 2016–2017 data is close to the values determined for the 2001–2015 set.