Search Publications
Comparison of Direct Magnetic Field Measurements in a Sunspot by Ten Spectral Lines of Fe I, Fe II, Ti I, and Ti II
Lozitsky, V. G.; Lozitska, N. I.; Yakovkin, I. I. +1 more
Direct magnetic field measurements in sunspots by many spectral lines are important for elucidating the true magnitude and structure of the magnetic field at different levels of the solar atmosphere. Currently, magnetographic measurements are the most widespread, but such measurements mainly represent the longitudinal component of the magnetic fie…
Propagation of Galactic Cosmic Rays in the Heliosphere during Minimum Solar Activity Periods
Fedorov, Yu. I.
Based on the cosmic ray transport equation, the propagation of charged high-energy particles in heliospheric magnetic fields is considered. The transport equation solution is found in the approximation of low anisotropy in the angular distribution of particles. The energy distribution of galactic cosmic rays at a heliopause is used as a boundary c…
Statistical Analysis of the Probability of Interaction of Globular Clusters with Each Other and with the Galactic Center on the Cosmological Time Scale According to Gaia DR2 Data
Ishchenko, M.; Sobolenko, M.; Berczik, P. +1 more
This study is aimed at investigating the dynamic evolution of the orbits of stellar globular clusters (SGCs). To integrate the orbits backward in time, the authors use models of the time-varying potentials derived from cosmological simulations, which are closest to the potential of the Galaxy. This allows for estimating the probability of close pa…
Convective Line Shifts in the Spectra of Solar-Type Stars
Sheminova, V. A.
The Doppler line shifts in the spectra of the Sun and stars with effective temperatures from 4800 to 6200 K were measured and the average convective (granulation) velocities were estimated. The absolute scale of the line shifts for the stars was established on the basis of the derived dependence of the shifts of solar lines on optical depth. For F…
Hyades Kinematics and the Relationship Between Galactic Coordinates and its Angular Distance from the Apex with Gaia EDR3
Elsanhoury, W. H.; Al-Johani, Amnah S.; Al-Juhani, Afaf +6 more
In this paper, we have improved the Hyades members with aid of the Gaia EDR3 source. We have studied their kinematics, including computations of the convergent point with AD-diagram method such as \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathr…
Variations in the Plasma Parameters of the Earth's Magnetotail during Substorm Initiation
Grigorenko, E. E.; Kronberg, E. A.; Kozak, L. V. +3 more
A chain of events accompanying the occurrence of a substorm in the Earth's ionosphere and magnetosphere is considered. Features of geomagnetic pulsations and mechanisms of their generation are indicated. Measurements of magnetic field fluctuations from fluxgate magnetometers, as well as the data on temperature, velocity, and concentration of elect…
Spectra of Turbulence during the Dipolarization of the Magnetic Field
Kozak, L.; Petrenko, B.; Kronberg, E. +3 more
The presence of heterogeneity in turbulent processes has been analyzed, and the spectra of turbulence have been obtained for the regions before and during the dipolarization of the magnetic field in the Earth's magnetospheric tail from the measurements of four space vehicles of the Cluster-2 mission (the event of September 21, 2005). The spectral …
Catalog of equatorial coordinates and B-magnitudes of stars of the Kitab part of the FON project
Ehgamberdiev, Sh. A.; Andruk, V. M.; Muminov, M. M. +3 more
The processing of the plates of the Kitab part of the FON project has been completed. In total, 1963 plates were processed. The catalog of equatorial coordinates α, δ, and B-magnitudes for 13 413268 stars and galaxies up to B ≤ 17.5m for the epoch 1984.97 is compiled. The Epson Expression 10000XL scanner with a 1200 dpi scanning mode an…
Photographic observations of Saturn's moons at the MAO NAS of Ukraine in 1961–1990
Andruk, V. M.; Pakuliak, L. K.; Yizhakevych, O. M.
A catalog of 1385 astrometric positions of Saturn's moons S2–S9 has been compiled with Tycho-2 as a reference frame from photographic observations obtained at the Main Astronomical Observatory, National Academy of Sciences of Ukraine, in 1961–1990. Astronegatives have been digitized with an Epson Expression 10000XL commercial scanner in 16-bit gra…
Catalog of equatorial coordinates and B-magnitudes of stars of the FON project
Andruk, V. M.; Pakuliak, L. K.; Golovnia, V. V. +4 more
The catalog of equatorial coordinates α and δ and B-magnitudes of stars of the northern sky (from–4° to +90°) was created as a part of the FON project at the Main Astronomical Observatory of the National Academy of Sciences of Ukraine. The data accumulated in the Joint Digital Archive of the Ukrainian Virtual Observatory were used. The total numbe…