Перегляд за Автор "Keir, L. E."

Зараз показуємо 1 - 5 з 5
  • Ескіз
    Документ
    Lithium-rich classical Cepheid V1033 Cyg: evolutionary status
    (Одеський національний університет імені І. І. Мечникова, 2019) Udovichenko, Serhii M.; Kovtyukh, Valery V.; Keir, L. E.; Удовиченко, Сергей Николаевич; Ковтюх, Валерій В.; Кеір, Л. Є.; Удовіченко, Сергій Миколайович
    We investigate evolutional status of cepheid V1033 Cyg in this work, its period of light variation consists 4 d .94 and the star is a real candidate on first crossing of instability stripe (IS) (as well as α of UMi). At first crossing of instability stripe, that lasts all close 1000 years, cepheids demonstrate the rapid increase of period, sometimes is a presence of strong line of lithium 6707 ˚A. Such objects knows only four in our Galaxy, one of them - V1033 Cyg. During included in a instability stripe amplitude of pulsations headily grows from a zero to some permanent size, and on leaving from (IS) - again falls to a zero. For verification this phenomenon in the Astronomical observatory of Odesa National University (Ukraine) on the 48-cm telescope AZT-3, equipped by CCD photometer with the optical sensor Sony ICX429ALL, a 1864 measuring of light V1033 Cyg were done in the filter of V and 713 in the filter R, that are partly presented in the Table. 1 and Fig. 2, and fully accessible to address http://cdsarc.ustrasbg.fr/viz-bin/cat. Considerable change of amplitude it is not got by us. The position of cepheid is certain by us in the (IS) - it appeared that star is near her center. In this phase evolutional to development and it must not be observed considerable change of amplitude (color index). The light curves, effective temperature and luminosity of V1033 Cyg are consistent with fundamental mode pulsation for a classical Cepheid on the center of the instability strip.
  • Ескіз
    Документ
    Monitoring of space objects using Odessa Observatory network of telescope
    (2019) Andrievsky, Serhii M.; Bazyey, N. V.; Zhukov, V. V.; Koshkin, Nikolay I.; Kashuba, V. I.; Kashuba, S. V.; Gorbanev, Yuriy M.; Sukhov, P. P.; Podlesnyak, S. V.; Udovichenko, S. N.; Keir, L. E.; Андрієвський, Сергій Михайлович; Андриевский, Сергей Михайлович; Кошкін, Микола Іванович; Кошкин, Николай Иванович; Горбаньов, Юрій Михайлович; Горбанёв, Юрий Михайлович
    In this paper we are presenting optical telescopes of Astronomical Observatory of I. I. Mechnikov Odessa National University. We are describing technical characteristics and scientific program for each telescope. Here we also present a description of the tools with which the unique collections of astroplates were obtained under the program “The Sky Service”. Odessa Observatory (46°.28 N, 30°.45 E, altitude 64 m, observation code 086) it has several observational stations. Among them: Mayaki (46.39° N, 30°.27 E, altitude 25 m, observation code 583) and Kryzhanovka (46°.37 N, 30°.48 E, altitude 40 m, observation code A85). Both stations have a good geographical location, as well as good astroclimate (up to 200 clear nights or part of the night). Telescopes are equipped with modern CCDs and photometric light detectors. Odessa Observatory has its own mechanical and optical workshops that are used for construction the new telescopes and manufacture and repair other astronomical equipment.
  • Ескіз
    Документ
    On the irregular variations in the light curves of RY Vul
    (Одеський національний університет імені І. І. Мечникова, 2018) Udovichenko, Serhii M.; Keir, L. E.; Удовиченко, Сергей Николаевич; Кеір, Л. Є.; Удовіченко, Сергій Миколайович
    In the Astronomical observatory of the Odesa National University traditionally study variable stars of different types: pulsating, double, irregular et al. By photometric observations it is possible to set the type of variable star, period of the brightness changes, spectral class, to estimate the temperature of surface. For observations variable stars there was the chosen area of star sky from by two stars Y Vul and RY Vul in the distance not more than 15 angular minutes (angular size of one frame). For these stars was got more than 5900 images during 56 nights during observant seasons 2011-2017. For all observations were got the curves of light variations. Results are for variable star Y Vul (type RR Lyr) published separately, and in this publication we bring results over of observation for star RY Vul. The star RY Vul according General Catalogue of Variable Star (GCVS) is RR Lyr variable, but period and initial epoch are unknown. To determine these parameters the photometric observations during several seasons in 2011-2017 of the variable star RY Vul on the Astronomical station near Odessa have been carried out. The 48-em telescope reflector AZT-3 equipped with CCD photometer was used. The light curves in V and R band were obtained and analyzed. It turned out that the light curves of the star is fully irregular. Therefore, the variable star RY Vul should be attribute to type "irregular variables".
  • Ескіз
    Документ
    Photometry and Blazhko effect in RR LYR-Type star AE Leo
    (Одеський національний університет імені І. І. Мечникова, 2017) Udovichenko, S. N.; Keir, L. E.
    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.
  • Ескіз
    Документ
    Photometry and the Blazhko effect in the RR Lyr variable star Y Vul
    (Одеський національний університет імені І. І. Мечникова, 2020) Udovichenko, S. N.; Keir, L. E.
    The RR Lyr variable star Y Vul have been observed by using a CCD photometer during several seasons from 2011 to 2017. Nearly 5960 data points were obtained spanning over 53 nights. We found the amplitude and phase modulations with the amplitudes of 0.16 mag and 0.041 of the pulsating phase in V filter; 0.15 mag and 0.041 of the pulsating phase in R filter, respectively. The frequency Fourier analysis of the light curves with the help of Period04 software was performed, Blazhko modulation period (59.20 days) and triplet structures in the Fourier spectrum were detected. The pulsation frequency components in the Fourier spectrum were identified up to the 7th harmonic order, while the modulation side lobe frequencies – up to 9th order. The analysis of the light curves maxima resulted in the same value of the Blazhko period. The fundamental pulsation period of the star has been practically stable over a period of a hundred years.