Search Publications
Improving the Orbits of Four Visual Binaries Using Gaia DR2 Data and Observations with the 26-inch Refractor of Pulkovo Observatory
Romanenko, L. G.; Izmailov, I. S.
We use a modified method of the apparent motion parameters (AMP), in which the initial data from the Gaia DR2 catalog are not only high-precision coordinates, parallaxes, and radial velocities of the components of the studied wide binary stars, but are also their proper motions. The coincidence of the AMP orbits obtained both from the Gaia DR2 dat…
How We Can Account for Type Ia Supernova Environment in Cosmological Analysis
Pruzhinskaya, M. V.; Pauna, N.; Novinskaya, A. K. +1 more
Among the other types of supernovae, Type Ia Supernovae (SNe Ia) have less luminosity dispersion at maximum light and show higher optical luminosities. These properties allow to use them as cosmological distance indicators that led to the discovery of the accelerating expansion of the Universe. However, even after the luminosity correction for str…
Contribution of Binary Stars to the Velocity Dispersion inside OB Associations with Gaia DR2 Data
Melnik, A. M.; Dambis, A. K.
We estimated the contribution of binary systems to the velocity dispersion inside OB-associations derived from Gaia DR2 proper motions. The maximum contribution to the velocity dispersion is given by the systems with the period of revolution of $P = 5.9$ yr whose components shift by a distance of about the diameter of the system during the base-li…
Properties of Stellar Populations of Eight Galactic Global Clusters with Low Central Surface Brightness
Sharina, M. E.; Maricheva, M. I.
This paper presents the results of the analysis of the integrated-light spectra of eight Galactic globular clusters with a relatively low luminosity and stellar density: Palomar 1, Palomar 2, Palomar 10, Palomar 13, Palomar 14, NGC 6426, NGC 6535, and NGC 6749. The absorption spectral indices in the Lick system were measured in their spectra, as w…
Oxygen Atom Escape from the Martian Atmosphere during Proton Auroral Events
Shematovich, V. I.; Kalinicheva, E. S.
We present the model calculation results of the atomic oxygen loss rate from the Martian atmosphere induced by precipitation of high-energy protons and hydrogen atoms (H/H+) from the solar wind plasma. Penetration of energetic protons and hydrogen atoms from the solar wind plasma to the upper atmosphere of Mars at altitudes of 100-250 k…
New Expansion Rate Estimate of the Scorpius-Centaurus Association Based on T Tauri Stars from the Gaia DR2 Catalog
Bobylev, V. V.; Baykova, A. T.
The kinematic properties of the Scorpius-Centaurus association were studied using spatial velocities of approximately 700 young T Tauri stars. Their proper motions and trigonometric parallaxes were selected by Zari et al. from the Gaia DR2 catalog, and radial velocities were taken from various sources. The linear expansion coefficient's new estima…
Binary Star Population with Common Proper Motion in Gaia DR2
Kovaleva, D. A.; Malkov, O. Yu.; Sapozhnikov, S. A. +1 more
<sec id="ASec1"><title>Abstract—We describe a homogeneous catalog compilation of common proper motion stars based on Gaia DR2. A preliminary list of all pairs of stars within the radius of 100 pc around the Sun with a separation less than a parsec was compiled. Also, a subset of comoving pairs, wide binary stars, was selected. The clus…
Kinematic Properties of Young Intermediate- and Low-Mass Stars from the Gaia DR2 Catalogue
Bobylev, V. V.; Bajkova, A. T.
We have studied the kinematic properties of young pre-main-sequence stars. We have selected these stars based on data from the Gaia DR2 catalogue by invoking a number of photometric infrared surveys. Using 4564 stars with parallax errors less than 20%, we have found the following parameters of the angular velocity of Galactic rotation: km s-1…
Solar System Encounters with Open Star Clusters
Vereshchagin, S. V.; Chupina, N. V.; Sizova, M. D. +1 more
The time and minimum distances of approaches were calculated more than 100 open star clusters (OSCs) near the Solar System over the past 5 Myr. It was shown that the closest proximity of the centers of the OSCs to the Solar System usually exceeded 60 pc. The Hyades cluster approached the Solar System at ~25 pc. The effect of such encounters on the…
Physical and Chemical Properties of Galactic Global Clusters with Various Origins Identified from the Gaia DR2 Data
Marsakov, V. A.; Koval', V. V.; Gozha, M. L.
The differences in the relationships between the physical parameters and the chemical-element abundances in accreted globular star clusters and those formed inside the Galaxy have been investigated. The information on the supposed formation sites of the clusters based on the Gaia DR2 data is borrowed from the literature. Those sources estimate the…