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Long-term Speckle Interferometric Monitoring of Binary Systems:2007–2023Positional Measurements and Orbits of Seven Objects

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Research in Astronomy and Astrophysics 2024年第9期24卷 147-155页

作者： Arina Mitrofanova Vladimir Dyachenko Anatoly Beskakotov Yuri Balega Alexander Maksimov Denis Rastegaev Special astrophysical observatory 369167 Nizhnij ArkhyzRussia

The results of seventeen years of speckle interferometric monitoring of seven objects(Chara 122Aa,GJ 3010,HIP1987,GJ 3076,HIP 11253,HIP 11352,and HIP 14929)are *** data were obtained at the 6 m Big Telescope Alt-azimuthal Special astrophysical observatory of the Russian Academy of Science(BTA SAO RAS)from 2007 to the *** of previously published and new measurements made it possible to construct completely new orbits for Chara 122Aa,HIP 11253,and HIP *** orbit of GJ 3076 cannot be constructed accurately due to the large influence of the weights assigned to the *** resulting orbital solutions are classified based on a grading scheme suggested by ***,*** and ***;most orbits are“definitive”(Grade 1).The mass sums and masses of components calculated by two independent methods using Hipparcos and Gaia DR2 and DR3 parallaxes were compared for the objects under study.

关键词： techniques:high angular resolution (stars:)binaries:visual stars:fundamental parameters stars:low-mass stars:solar-type

Diffuse matter and cosmogony of stellar systems in researches by ***

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Research in Astronomy and Astrophysics 2018年第8期18卷 89-96页

作者： Natalia Ivanovna Bondar Crimean astrophysical observatory RAS Nauchny298409Russia

The main topic of long-term researches by G.A. Shajn is the nature of diffuse matter, its dis- tribution in the Galaxy and extragalactic systems, interaction with the interstellar medium and hot stars, and the formation of emission and reflection nebulae and stars. Based on the analysis of experimental data, mainly photographic observations of nebulae in the Milky Way and extragalactic systems, he made conclusions and suggested well-founded hypotheses on a wide range of considered problems, including those related to cosmogony. The structure of nebulae, and their masses and sizes give reasons behind the conclusion that most of them are formed not in the process of ejection of matter from the stars, but rather they are objects which are born and evolve, and quite often are comprised of giant conglomerates of gas, dust and stars. The distribution of OB-type stars and nebulae in spiral branches points to their genetic relation and the fundamental role of the interstellar medium as the source of their formation. The structural features of nebulae are determined by the action of magnetohydrodynamic forces. Magnetic fields in a galaxy control the motion of diffuse gas-dust matter and ensure the maintenance of its spiral structure. These ideas continue being developed in modern directions of astrophysics.

关键词： galaxy interstellar matter diffuse nebulae cosmogony

A Statistical Study of Magnetic Flux Emergence in Solar Active Regions Prior to Strongest Flares

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Research in Astronomy and Astrophysics 2024年第4期24卷 147-160页

作者： Alexander S.Kutsenko Valentina I.Abramenko Andrei A.Plotnikov Crimean astrophysical observatory p/o NauchnyCrimea298409Russia

Using the data on magnetic field maps and continuum intensity for Solar Cycles 23 and 24,we explored 100 active regions(ARs)that produced M5.0 or stronger *** focus on the presence/absence of the emergence of magnetic flux in these ARs 2-3 days before the strong flare *** found that 29 ARs in the sample emerged monotonically amidst quiet-Sun.A major emergence of a new magnetic flux within a pre-existing AR yielding the formation of a complex flare-productive configuration was observed in another 24 *** 30 ARs,an insignificant(in terms of the total magnetic flux of pre-existing AR)emergence of a new magnetic flux within the pre-existing magnetic configuration was observed;for some of them the emergence resulted in a formation of a configuration with a small δ-sunspot;11 out of 100 ARs exhibited no signatures of magnetic flux emergence during the entire interval of *** six cases the emergence was in progress when the AR appeared on the Eastern limb,so that the classification and timing of emergence were not *** conclude that the recent flux emergence is not a necessary and/or sufficient condition for strong flaring of an *** flux emergence rate of flare-productive ARs analyzed here was compared with that of flare-quiet ARs analyzed in our previous *** revealed that the flare-productive ARs tend to display faster emergence than the flare-quiet ones do.

关键词： Sun:activity Sun:flares Sun:magnetic fields

Simultaneous photometric and spectral analysis of a new outburst of V1686 Cyg

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Research in Astronomy and Astrophysics 2020年第4期20卷 81-86页

作者： Hasmik Andreasyan Tigran Magakian Tigran Movsessian Byurakan astrophysical observatory NAS RAByurakanAragatzotn Prov.0213Armenia

We present an analysis of the optical observations of Herbig Ae/Be(HAeBe)star V1686 Cyg,which is associated with a small isolated star-forming region around HAeBe star BD+40?*** observed this star as a part of our project investigating young eruptive *** were conducted on the 2.6-m telescope of Byurakan observatory from 2015 to *** this period,we obtained direct images of V1686 Cyg and 14 medium-and low-resolution *** the course of observations,we noticed that this star underwent an atypical brightness *** data reduction,we found that the full rise and decline in the brightness of V1686 Cyg had an amplitude of almost 3 magnitudes and lasted about 3 *** were also able to track changes in the stellar spectrum during the outburst,which are correlated with the photometric variations.

关键词： stars:pre-main sequence stars:variables:T Tauri Herbig Ae/Be stars:individual:(V1686 Cyg)

On the correctness of orbital solutions obtained from a small set of *** of HIP 53731

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Research in Astronomy and Astrophysics 2020年第11期20卷 321-324页

作者： Arina Mitrofanova Vladimir Dyachenko Anatoly Beskakotov Yury Balega Alexander Maksimov Denis Rastegaev Sergey Komarinsky Special astrophysical observatory of the Russian Academy of Sciences Nizhnij ArkhyzRussia 369167

HIP 53731 is a binary consisting of stars of the spectral types K0 and *** orbit of this object was constructed previously by Cvetkovic et *** improved by *** should be noted that there is a 180°ambiguity in the position angles of some published *** interferometric observations were obtained in 2007–2020(21 measurements)at the 6-m telescope of the SAO RAS(BTA)by the authors of this *** analysis of new data together with previously published ones made it possible to construct an accurate orbit of HIP 53731 and to halve the already known values of the orbital period of the *** a result of the study,the mass sum,the masses of each component and their spectral types were determined by two independent *** to the qualitative classification of orbits,the orbital solution has grade 2–"good"(observations cover more than half of the orbital period and correspond to different phases).

关键词： techniques high angular resolution,speckle interferometry stars low-mass,fundamental parameters stars binaries spectroscopic stars individual HIP 53731

Spectral study of V565 Mon: probable FU Ori-like or chemically peculiar star

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Research in Astronomy and Astrophysics 2021年第3期21卷 128-132页

作者： Hasmik Andreasyan Byurakan astrophysical observatory NAS RAByurakanAragatzotn Prov.0213Armenia

We present a detailed spectroscopic study of pre-main sequence star V565 Mon,which is the illuminating star of the Parsamian 17 cometary *** were performed with the 2.6 m telescope in Byurakan astrophysical observatory on 2018 February *** velocities and equivalent widths of the most prominent lines of V565 Mon are *** build the spectral energy distribution and estimate the main parameters of the star,for example the obtained bolometric luminosity of V565 Mon is L_(V565)≈130 L_(⊙).Considering all features of V565 Mon,we come to the conclusion that this young intermediate-mass star belongs to some intermediate class between T Tau and HAeBe *** unusual for a young star is the presence of strong absorption BaⅡlines in the *** explanations on this issue are ***,we think that V565 Mon is a unique example,which can help to understand some open questions involved in the problem of nucleosynthesis in young stars.

关键词： stars:pre-main sequence stars:variables:T Tauri Herbig Ae/Be stars:individual:V565 Mon

GSC 4560–02157: a new long-period eclipsing cataclysmic variable star

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Research in Astronomy and Astrophysics 2015年第7期15卷 1005-1011页

作者： Anton V.Khruslov Anatoly V.Kusakin Elena A.Barsukova Vitaly P.Goranskij Azamat F.Valeev Nikolay N.Samus Institute of Astronomy Russian Academy of Sciences Fesenkov astrophysical Institute Special astrophysical observatory Russian Academy of Sciences Sternberg Astronomical Institute Lomonosov Moscow State University

We study the newly discovered variable star GSC 4560-02157. CCD photometry was performed in 2013-2014 at the Tien Shan Astronomical observatory,and a spectrum was obtained with the 6-m telescope of the Special astrophysical observatory in June, 2014. GSC 4560-02157 is demonstrated to be an eclipsing variable star（P = 0.265359d）. All its flat-bottom primary minima are approximately at the same brightness level, but the star＇s out-of-eclipse brightness and brightness at secondary minima vary considerably（by up to 0.6m） from cycle to cycle. Moreover,there are short-term（time scale of 0.03-0.04 days） small-amplitude brightness variations out of eclipse. This behavior suggests a cataclysmic nature for the star, which is confirmed with a spectrum taken on 2014 June 5. The spectrum shows numerous emissions of the hydrogen Balmer series, He Ⅰ and He Ⅱ.

关键词： stars: dwarf novae -- binaries: eclipsing -- stars: individual: GSC 4560-02157

Physical Background of the Unified Scaling Law in Spiral Galaxies

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Chinese Physics Letters 2000年第12期17卷 935-936页

作者： ZOU Zhen-Long HAN Jin-Lin Beijing Astronomical observatory and Beijing astrophysical Center National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100012

We discussed the physical background of the unified scaling law in spiral galaxies,and qualitatively obtained the power index of the empirical relation among the luminosity L,radius R and the rotation velocity *** also discussed the possible causes for the data dispersion on the plane in three-dimensional space of these parameters.

关键词： parameters galaxies rotation

Analysis of X-Ray Emission from OB Stars. IV. About X-Ray Emission from Inhomogeneous Winds of OB Stars

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Research in Astronomy and Astrophysics 2023年第10期23卷 387-405页

作者： Elizaveta Ryspaeva Alexander Kholtygin Crimean astrophysical observatory NauchnyCrimeaRussia Saint-Petersburg State University Saint-PetersburgRussia

We study the origin of X-ray emission from OB stars due to collisions of stellar winds and/or inhomogeneities in the winds. The low-resolution X-ray spectra of a big sample of OB stars were fitted by both the stationary APEC/MEKAL models and by this model with an additional PSHOCK component describing the nonstationary X-ray emission. These spectra were also described by two-temperature PSHOCK models. More than ~50% of considered spectra can be described by the above-mentioned model combinations including the PSHOCK model and the quality of the fits appears to be better for O stars. The plasma temperature of the PSHOCK component is about 1–5 keV with the ionization timescale τ_(u)~ 10^(8)–10^(13)s cm^(-3). The temperature of the PSHOCK component increases with the momentum and kinetic energy of the stellar wind by a power law with an index ~0.12–*** dependencies were not revealed through modeling by the stationary APEC/MEKAL models only. At the same time the X-ray luminosity of OB stars depends on momentum and kinetic energy of their winds similarly either for stationary or for nonstationary models. We conclude that many O stars and some B stars can be sources of the nonstationary X-rays formed in their inhomogeneous stellar wind.

关键词： stars:early-type stars:statistics X-rays:stars