Том 100, № 9 (2023)

The paper is dedicated to the memory and scientific heritage of Marij Anatolyevich Svechnikov, an outstanding researcher and teacher, founder of the Ural school of study of close binary systems and author of the classification of eclipsing variable stars. The paper provides a brief overview of the major life events and main scientific achievements of M.A. Svechnikov. The best memory is the continuation and development of those s-cientific directions to which he devoted his scientific activity. The research initiated by M.A. Svechnikov was continued in the works of his apprentices and followers at the Ural State University, Chelyabinsk State University, Chita State University, etc. The paper is based on a talk presented at the astrophysical memorial seminar “Novelties in Understanding the Evolution of Binary Stars”, dedicated to the 90th anniversary of Professor M.A. Svechnikov.

The diversity of close binary stars (CBS) and the rich manifestation of their activity as a result of the interaction of stellar components have turned their observed family into a very developed and effective tool for studying the evolution of stars. This review presents the main features of modern ideas about the evolution of CBS from their origin to the formation of finite compact remnants of components: degenerate dwarfs, neutron stars and stellar black holes. The main phenomena related to their interaction with each other and accompanying the process of fusion of compact components of the CBS are also listed, taking into account the effect of common envelopes, radiation of gravitational waves in cataclysmic and X-ray binaries, supernovae (SN Ia, SN Ib), gamma-bursters and other systems. The paper is based on a talk presented at the astrophysical memorial seminar “Novelties in Understanding the Evolution of Binary Stars”, dedicated to the 90th anniversary of Professor M.A. Svechnikov.

We present results of a new spectroscopic study of a close binary system with massive components UU Cas based on the spectra obtained with the echelle spectrometer on the 1.2m telescope of the UrFU Kourovka Astronomical Observatory from 2017 to 2022. The results of this study confirm the new evolutionary status of UU Cas previously determined by the author with the spectrophotometry of this system in 2017 and confirmed in a number of works by other researchers. According to these studies, the system is in the final stage of the mass exchange process, but not at its beginning, as previously thought. The components of UU Cas are not very massive, and the ratio of their masses is opposite to a ratio determined earlier from the results of photometry. The parameters of the binary system were obtained on the more extensive observational material. This new parameters differ only slightly from those obtained earlier by the author. The half-amplitudes of the radial velocities are \({{K}_{1}} = 195.6\) km s^–1, \({{K}_{2}} = 106.5\) km s^–1. The masses of the components are \({{M}_{1}} = 9.6\;{{M}_{ \odot }}\), \({{M}_{2}} = 17.6\;{{M}_{ \odot }}\) for the orbital inclination i = 74.5°. The orbital radius of this close binary is \(A = 54.2\;{{R}_{ \odot }}\). The paper is based on a talk presented at the astrophysical memorial seminar “Novelties in Understanding the Evolution of Binary Stars”, dedicated to the 90th anniversary of Professor M.A. Svechnikov.

We collected the information about 83 pre-main sequence double-lined spectroscopic binaries. Among them there are Ae/Be Herbig stars, T Tauri stars and red dwarfs. The eccentricity – period relation, the mass ratio and eccentricity distributions of young spectroscopic binaries are constructed and analyzed. The overwhelming majority of close binaries with \(P < {{10}^{d}}\) have eccentricity near to zero, the stars less than 1 million years old are rare among them. The mass ratio distribution of systems with \(P < {{10}^{d}}\) has a prominent maximum in a range of \(q = 0.9{\kern 1pt} - {\kern 1pt} 1.0\). The number of young spectroscopic binaries with \(P > {{10}^{d}}\) does not decrease with decreasing mass ratio as sharply as in the case of close binary stars, about 12% of these stars have \(q < 0.5\). The paper is based on a talk presented at the astrophysical memorial seminar “Novelties in Understanding the Evolution of Binary Stars”, dedicated to the 90th anniversary of Professor M.A. Svechnikov.

We use the catalog of wide binary stars [1], created on the basis of Gaia EDR3 and including more than a million pairs, to analyze Gaia DR3 data independently obtained for the components of the pairs. It is shown that the spatial heterogeneity of the catalog reflects the Gaia scanning law. The change in the spatial density of binary stars of the catalog with increasing distance from the Sun is investigated. By comparison with the model distribution, it is shown that the catalog contains approximately 2.5 times fewer binary stars than would be expected without spatial incompleteness. It is confirmed that the radius of spatial completeness of the catalog is on average close to 200 pc and depends on the absolute magnitude of the main component. The spatial density of binary stars in the catalog mildly depends on the difference in the stellar magnitudes of the components, and significantly depends on the physical distance between the components. The incompleteness of the catalog in relation to pairs with a distance between components less than 100 AU occurs already at a distance of 25 pc from the Sun. A comparison of the characteristics of components of the same pair independently determined within the Gaia DR3 catalog allows us to investigate how the probability of a non-random combination of components is related to the proximity of their characteristics. A high degree of correlation of the degree of agreement of the characteristics with the reliability of the pair is found for radial velocities. Qualitative agreement is observed for the metallicity estimates of [Fe/H] and, to a lesser extent, for the absorption estimates of \({{A}_{G}}\). No agreement was found for the ages of the stars, which indicates their significant uncertainty in the dataset consisting mainly of main sequence stars. At the same time, age estimates for pairs with evolved components show noticeably better agreement than for the dataset as a whole. Using the parameters of the components of pairs from Gaia DR3, an independent estimation of the uncertainties of the values of radial velocities and metallicities depending on the apparent magnitude G of the sources was performed. Estimates of probable median values of radial velocity errors and metallicity of Gaia DR3 sources are proposed. Depending on the apparent magnitude, they exceed the median values of errors given in the catalog: for radial velocities by 1.5–3 times, for metallicity [Fe/H] by 7–25 times. The paper is based on a talk presented at the astrophysical memorial seminar “Novelties in Understanding the Evolution of Binary Stars”, dedicated to the 90th anniversary of Professor M.A. Svechnikov.