Search Publications
Searching for new cataclysmic variables in different X-ray and optical catalogs
Galiullin, I. I.
Cataclysmic variables (CVs) are binary systems in which a white dwarf accretes matter from a Roche-lobe-filling companion star. Numerous CVs can be seen in optical light curves as periodic sources. Moreover, accretion can result in outbursts, which are visible in their optical light curves, especially in non-magnetic CVs. I review a modern multiwa…
Variable stars in the field of open cluster NGC 6819
Karimov, R. G.; Gaysin, R. A.
Here we present preliminary results of searching and study of variable stars based on space observation data of the TESS mission in the field of the open star cluster NGC 6819. The light curves of variable stars of various types located in the field of an open cluster are studied. Based on the data from the GAIA DR3 mission, the probable members o…
Method of evaluation of the most probable mean radial velocities of open star clusters
Kovaleva, D. A.; Kalinkin, A. D.; Kondratev, N. E. +1 more
In this article the method of self-consistent estimate of star clusters' average radial velocity by kinematic parameters was proposed. The method is based on convergent point method of probable cluster members determination. By modelling the method validation was held and properties of received estimate depending on a number of cluster parameters …
Fundamental parameters of Ap-star HD 108662
Romanovskaya, A. M.; Ryabchikova, T. A.; Shulyak, D. V.
We present the results of self-consistent spectroscopic analysis of the atmosphere of Ap-star HD 108662 based on high resolution spectrum and spectrophotometric observations in a wide wavelength range. Magnetic field effects were taking into account. Abundances of 24 chemical elements were derived, and stratification of Fe which lines make the mai…
Observational signs of wide binary stars dissolution in Gaia DR2 data
Kovaleva, D. A.; Sapozhnikov, S. A.
Binary and common proper motion stars within 100 pc of the Sun are being investigated using Gaia DR2 data. An artificial random pairs sample is constructed to exclude possible random pairing contamination. Numerical estimation of this contamination shows that the chosen method to select the common proper motion stars yields little contamination ev…
The kinematics of OB-stars and Cepheids based on Gaia DR2 catalogue
Pakhomova, P. V.
The purpose of the work was to study the kinematics and refine the distance scale of young objects of the galactic disk: OB stars and high-luminosity stars of late spectral classes, as well as Cepheids. We used the observational data obtained during the Gaia mission and published in the Gaia DR2 catalog. The statistical parallax method was used to…
On possibility using photometry of Landolt fields for determination of stellar parameters and interstellar reddening
Pakhomov, Yu. V.; Stepina, Yu. A.
The paper analyzes the possibility of determination of stellar parameters and interstellar reddening based on UBVRIJHK photometry of secondary standards of the Landolt field S98. It is shown that the accuracy of photometric measurements should be 0.010 - 0.015 m or better and, at least 0.02 m , if a measured parallax is available.
Objects of the Catalog of Orbits of Visual Binary Stars in Gaia DR2
Chulkov, D. A.
Cross-identification is made for the Catalog of Orbits of Visual Binary Stars and Gaia DR2. At least one component has been matched for 88% systems, for 15% identification is available for both stars. Systems with substantially different parallaxes of components are found, which are the candidates to be the optical pairs. It's shown that published…
Distribution of visual binary stars over masses and separation between components
Tutukov, A. V.; Kovaleva, D. A.
We investigate initial ditributions of visual binary stars over semimajor axes of orbits, initial masses of main components, and mass ratios of components using complete data on wide stellar pairs from WDS catalogue and results of astrometric space missions Gaia and Hipparcos.
Red supergiants in Galaxy and in galaxies
Kovaleva, D. A.
We use Gaia DR2 data to compare distribution of Milky Way red supergiants over absolute stellar magnitude M Ks with similar distributions produced by RSG's in other galaxies (M31, M33, LMC, SMC). In spite of their different metallicities, three galaxies: MW, M31 and SMC - provide similar distributions, while the RSG's from M33 and LMC are differen…