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  • The Change of Period and Obliquity Angle of Pulsar under Braking of Magnetic Dipolar Radiation and Magnetic Decay
    Astron. Rep. (IF 1.164) Pub Date : 2020-12-30
    Lin-Sen Li

    Abstract The change of pulsar period and inclination angle under the braking of magnetic radiation and magnetic decay is studied. The system of equations for evolution of period and inclination angle with time is given and solved. The solution shows that the period increases, and the inclination angle decreases with time under the braking of magnetic radiation and decay. The numerical results for the

    更新日期:2020-12-30
  • Physical Libration of the Moon: An Extended Problem
    Astron. Rep. (IF 1.164) Pub Date : 2020-12-30
    A. A. Zagidullin, V. S. Usanin, N. K. Petrova, Yu. A. Nefedyev, A. O. Andreev, T. V. Gudkova

    Abstract The work is devoted to the study of the physical libration of the Moon. Interest in the traditional topic related to the rotation of the Moon is stirred up by the activity of many countries regarding the development of circumlunar space. Scientifically, the main agenda is to consider the viscosity of the core. At this stage of the theory development, such effects as indirect and direct perturbations

    更新日期:2020-12-30
  • The Relic Neutrino Composition as Seen from Earth
    Astron. Rep. (IF 1.164) Pub Date : 2020-12-30
    A. N. Baushev

    Abstract Being generated, the relic neutrino background contained equal fractions of electron \({{\nu }_{e}}\), muon \({{\nu }_{\mu }}\), and taon \({{\nu }_{\tau }}\) neutrinos. We show that the gravitational field of our Galaxy and other nearby cosmic objects changes this composition near the Solar System. As a result, the relic background becomes enriched with taon and particularly muon neutrinos

    更新日期:2020-12-30
  • On the Influence of Angular Momentum and Dynamical Friction on Structure Formation
    Astron. Rep. (IF 1.164) Pub Date : 2020-12-30
    Antonino Del Popolo

    Abstract In this paper we extended the spherical collapse model to take account of angular momentum and dynamical friction and studied how the accreted mass, the threshold of collapse, the virial overdensity, and the mass function change. Solving the equation of motion we got the relationships between mass, M, and the turn-around radius, \({{R}_{0}}\). This relation is important because knowing \({{R}_{0}}\)

    更新日期:2020-12-30
  • Multi-Brid DBI Inflation
    Astron. Rep. (IF 1.164) Pub Date : 2020-12-30
    S. Khoeini-Moghaddam

    Abstract It is shown that it is possible to extend the application of \(\delta \mathcal{N}\) formalism to some special separable non-canonic cases. In this work, we extended the multi-brid idea to the multi-field separable model with a non-canonical kinetic term, mainly DBI (Dirac–Born–Infeld) action. Multi-brid stands for multi-component hybrid inflation which is based on δN formalism. To be more

    更新日期:2020-12-30
  • TianQin Space-Based Gravitational Wave Detector: Key Technologies and Current State of Implementation
    Astron. Rep. (IF 1.164) Pub Date : 2020-12-30
    V. K. Milyukov

    Abstract TianQin is a project of a space-based gravitational wave detector for detecting GW events in the millihertz frequency range. The space-based detector must be implemented on three identical drag-free spacecraft orbiting around the Earth. The key technologies that form the principles of operation of the space-based GW detector are, first, an ultrastable transponder laser interferometer and,

    更新日期:2020-12-30
  • Kinematic Properties of Young Intermediate- and Low-Mass Stars from the Gaia DR2 Catalogue
    Astron. Rep. (IF 1.164) Pub Date : 2020-12-30
    V. V. Bobylev, A. T. Bajkova

    Abstract 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: \({{\Omega }_{0}} = 28.84 \pm 0.10\) km s–1 kpc–1, \(\Omega

    更新日期:2020-12-30
  • Solution of Kepler’s Equation with Machine Precision
    Astron. Rep. (IF 1.164) Pub Date : 2020-12-30
    M. K. Abubekerov, N. Yu. Gostev

    Abstract— An algorithm for the numerical solution of Kepler’s equation with machine precision is presented. The convergence of the iterative sequence of Newton’s method is proved for the indicated initial approximation. The problem of finding a numerical solution to Kepler’s equation as a floating point number is formulated. Aspects related to computations near machine zero are taken into account.

    更新日期:2020-12-30
  • Changing Looks of the Nucleus of Seyfert Galaxy NGC 3516 during 2016–2020
    Astron. Rep. (IF 1.164) Pub Date : 2020-12-30
    V. L. Oknyansky, Kh. M. Mikailov, N. A. Huseynov

    Abstract The results of spectral observations of NGC 3516 with the 2-m telescope of the Shamakhy Astrophysical Observatory during 2016–2019 are presented. In the first half of 2016, the intensive broad component H\(\beta \) was found, which indicates a spectral type change compared to 2014, when the broad component was almost invisible. In the second half of 2016, the broad component H\(\beta \) again

    更新日期:2020-12-30
  • The κ-Cygnid Meteor Shower and Its Relationship with Near-Earth Asteroids
    Astron. Rep. (IF 1.164) Pub Date : 2020-12-30
    M. V. Sergienko, M. G. Sokolova, Yu. A. Nefedyev, A. O. Andreev

    Abstract— This study is focused on the relationships between the κ-Cygnid meteor shower and different groups of asteroids crossing the Earth’s orbit (the so-called near-Earth objects (NEOs)). The analysis is based on the visible structure of the meteor shower and a comprehensive strategy for estimating the proximity of orbits of two bodies. The κ-Cygnid meteor shower (abbreviated as KCG) is observed

    更新日期:2020-12-30
  • Lunar-Based Measurements of the Moon’s Physical Libration: Methods and Accuracy Estimates
    Astron. Rep. (IF 1.164) Pub Date : 2020-12-30
    N. K. Petrova, Yu. A. Nefedyev, A. O. Andreev, A. A. Zagidullin

    Abstract Computer simulation results are reported for planned lunar-based observations to be conducted using an automated zenith telescope that can be placed at any lunar latitude. Benefits of lunar-based observations are shown, in comparison with lunar laser ranging. It is investigated whether, and how effectively, these observations can be used to determine the lunar rotation parameters (physical

    更新日期:2020-12-30
  • Strong Shock in the Uniformly Expanding Universe with a Spherical Void
    Astron. Rep. (IF 1.164) Pub Date : 2020-12-30
    G. S. Bisnovatyi-Kogan, S. A. Panafidina

    Abstract Propagation of a strong shock wave in the expanding universe is studied using approximate analytic and exact numerical solution of self-similar equations. Both solutions have similar properties, which change qualitatively, depending on the adiabatic powers γ. In the interval \(1 < \gamma < {{\gamma }_{{{\text{cr}}}}} \sim 1.16\) analytic and numeric solutions fill all the space without any

    更新日期:2020-12-30
  • Nature of Purely Stellar Rings in Lenticular Galaxies
    Astron. Rep. (IF 1.164) Pub Date : 2020-12-30
    O. K. Sil’chenko

    Abstract The origin of several rings in lenticular galaxies with no signs of ongoing or recent star formation (without emission lines and a signal in the ultraviolet spectral range) is investigated. Stellar population parameters—the average age and the magnesium–iron ratio—are measured; structural features are analyzed. It is concluded that the rings in all the galaxies have a different history of

    更新日期:2020-12-30
  • Migration of Hot Jupiters Induced by Atmosphere Outflow
    Astron. Rep. (IF 1.164) Pub Date : 2020-12-30
    E. P. Kurbatov, D. V. Bisikalo, I. F. Shaikhislamov

    Abstract— As is known, the influence of the ionizing radiation and the gravity of a star on a hot Jupiter results in the outflow of its atmosphere. Due to the gravity of the planet, the outflowing matter acquires angular momentum, after which it is accumulated on a higher circular orbit around the star and forms a disk or a torus. The angular momentum interexchange between the torus and the planet

    更新日期:2020-12-30
  • Modeling of Hydrogen Emission Lines in the Spectrum of UX Ori in Its Bright State and during Eclipses
    Astron. Rep. (IF 1.164) Pub Date : 2020-12-30
    L. V. Tambovtseva, V. P. Grinin, D. V. Dmitriev

    Abstract— The hydrogen spectrum of the UX Ori-type star is modeled in a bright state and during an eclipse by an opaque dusty fragment of its own protoplanetary disk. The disk wind is considered as the main source of the emission spectrum. The radiation generated in the stellar magnetosphere is also taken into account. We showed that variations in the Hα line profile during eclipses depend sensitively

    更新日期:2020-12-30
  • Inverse Compton Scattering of Radiation from a Central Source as a Possible Mechanism for the Formation of X-Ray Radiation from Kiloparsec Jets of Core-Dominated Quasars
    Astron. Rep. (IF 1.164) Pub Date : 2020-11-17
    M. S. Butuzova, A. B. Pushkarev, E. S. Shablovinskaya, S. V. Nazarov

    Abstract For the interpretation of X-ray radiation from kiloparsec jets of quasars, the inverse Compton scattering of the cosmic microwave background has been widely used for almost 20 years. A recent analysis of the Fermi-LAT observational data showed that this assumption is inapplicable for jets of several quasars. In this paper, we consider the inverse Compton scattering of photons from a central

    更新日期:2020-11-17
  • Cyclical Changes in the Extraeclipse Brightness and the Period of W UMa-TYPE Close Binary System AM Leo
    Astron. Rep. (IF 1.164) Pub Date : 2020-11-17
    S. Yu. Gorda

    Abstract The results of 14-year photometric monitoring of the contact close binary system (CBS) W UMa-type AM Leo are presented. Low-amplitude cyclic variations in brightness with a period of \(7.6 \pm 0.3\) years, not associated with the phenomena of eclipses and tidal deformations of the components, as well as low-amplitude cyclic variations of the CBS period with practically the same value of the

    更新日期:2020-11-17
  • Galaxies in Observations and Numerical Models
    Astron. Rep. (IF 1.164) Pub Date : 2020-11-17
    M. Demianski, A. Doroshkevich, T. Larchenkova, S. Pilipenko

    Abstract A comparison of the virial parameters of galaxies and galaxy clusters (radius, density, and entropy function) in a wide range of masses, \({{10}^{6}} \leqslant {{M}_{{{\text{vir}}}}}{\text{/}}{{M}_{ \odot }} \leqslant {{10}^{{14}}}\), shows that these parameters are correlated and depend on the virial mass of an object in a regular way. For the observed galaxies and galaxy clusters the available

    更新日期:2020-11-17
  • Variations in the Orbital Period of the Eclipsing Binary System V505 Sgr
    Astron. Rep. (IF 1.164) Pub Date : 2020-11-17
    A. I. Khaliullina

    Abstract The variations in the orbital period of the eclipsing binary system V505 Sgr, which is a part of the visual binary system CHR 90, have been analyzed. It has been shown that the variations in the period can be represented as a superposition of the secular decrease in the period at a rate of 2.97 × 10–7 days/year and the light-time effect with a period of 72.8 years. The secular decrease in

    更新日期:2020-11-17
  • Autonomous Predictions Realized in Navigation Receivers for the Motion of GLONASS and GPS Spacecraft
    Astron. Rep. (IF 1.164) Pub Date : 2020-11-17
    S. M. Kudryavtsev

    Abstract— A new algorithm for autonomous long-term predictions realized in ground navigation receivers for ephemerides of GLONASS and GPS spacecraft is developed and analyzed. The algorithm can be applied to determinations of user’s coordinates, when it is impossible or difficult to receive the spacecraft ephemerides (for example, in conditions of a bad radio-visibility of the satellites). It is shown

    更新日期:2020-11-17
  • Generation of Unbound Comets and Planets by Planetary Systems
    Astron. Rep. (IF 1.164) Pub Date : 2020-11-17
    A. V. Tutukov, G. N. Dremova, V. V. Dremov

    Abstract We present a three-dimensional model of the evolution of the asteroid–cometary–planetary (ACP) component of the Solar System under the gravitational influence of Jupiter. We demonstrate the origin of the Kuiper belt of the Sun, the Oort cloud of the Sun and Jupiter, as well as the ACP “spear,” which becomes elongated with time and transforms into a “ring” of ACP objects along the trajectory

    更新日期:2020-11-17
  • Measuring Plumb-Line Deviations with a Digital Astrometer at the Moscow Gravitational Attraction
    Astron. Rep. (IF 1.164) Pub Date : 2020-10-10
    M. M. Murzabekov, V. F. Fateev, P. A. Yuzefovich

    Abstract The paper presents the component measurement results of plumb-line deviations (PLDs) with a digital astrometer at the Moscow gravitational anomaly (attraction). The anomaly was first discovered in the 1850s by B. Ya. Schweitzer, Professor of Astronomy of the Moscow University. The paper is based on the conference talk made at “Astronomy yesterday, today, tomorrow” (Sternberg Astronomical Institute

    更新日期:2020-10-11
  • Evolution of a Viscous Protoplanetary Disk with Convectively Unstable Regions. II. Accretion Regimes and Long-Term Dynamics
    Astron. Rep. (IF 1.164) Pub Date : 2020-10-10
    L. A. Maksimova, Ya. N. Pavlyuchenkov, A. V. Tutukov

    Abstract In this article, we proceed to study convection as a possible factor of episodic accretion in protoplanetary disks. Within the model presented in Article I, the accretion history is analyzed at different rates and areas of matter inflow from the envelope onto the disk. It is shown that the burst-like regime occurs in a wide range of parameters. The long-term evolution of the disk is also modeled

    更新日期:2020-10-11
  • Evolution of the OH and H 2 O Maser Emission in the Active Star-Forming Region IRAS 05358+3543 (S231)
    Astron. Rep. (IF 1.164) Pub Date : 2020-10-10
    N. T. Ashimbaeva, P. Colom, V. V. Krasnov, E. E. Lekht, M. I. Pashchenko, G. M. Rudnitskii, A. M. Tolmachev

    Abstract We present the results of our observations of the star-forming region located in the Perseus arm and associated with the Sharpless nebula S231 in the lines of H2O at a wavelength of 1.35 cm and OH at a wavelength of 18 cm obtained with the Pushchino 22-m radio telescope (Russia) and the Nançay Large Radio Telescope (France), respectively. We provide a catalog of H2O maser spectra in the period

    更新日期:2020-10-11
  • Physical and Chemical Properties of Galactic Global Clusters with Various Origins Identified from the Gaia DR2 Data
    Astron. Rep. (IF 1.164) Pub Date : 2020-10-10
    V. A. Marsakov, V. V. Koval’, M. L. Gozha

    Abstract 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 probability of belonging to the Galactic bulge

    更新日期:2020-10-11
  • Formation of Stellar Streams Due to the Decay of Star Clusters, OB Associations, and Galaxy Satellites
    Astron. Rep. (IF 1.164) Pub Date : 2020-10-10
    A. V. Tutukov, M. D. Sizova, S. V. Vereshchagin

    Abstract This paper presents a scenario of the evolution of OB associations and star clusters from formation to decay, in the process of which they turn into stellar streams moving in the disk and stellar “rings” around the galactic center. The scenario also includes the formation of stellar streams by galaxies absorbing their dwarf satellite galaxies. The simplest spatial kinematic models of evolution

    更新日期:2020-10-11
  • Kinetic Calculations of the Charge Exchange Efficiency for Solar Wind Protons in the Extended Martian Hydrogen Corona
    Astron. Rep. (IF 1.164) Pub Date : 2020-10-10
    V. I. Shematovich, D. V. Bisikalo

    Abstract— Model calculations of the charge exchange efficiency for solar wind protons colliding with hydrogen atoms of the extensive Martian corona are presented. It is shown that the energy spectrum of hydrogen atoms penetrating in the Martian atmosphere is identical to the spectrum of protons of the unperturbed solar wind. The charge exchange efficiency varies from 2 to 4% depending on the boundary

    更新日期:2020-10-11
  • Solar Quadrupole in Tensor Description
    Astron. Rep. (IF 1.164) Pub Date : 2020-10-10
    A. S. Shibalova, V. N. Obridko, D. D. Sokolov, V. V. Pipin

    Abstract The cyclic variations in the quadrupole component of the solar magnetic field is studied in tensor description. The results are consistent with the classical description of the quadrupole using spherical functions, and the mathematical apparatus of tensor algebra allows one to compare the observed changes in the magnetic quadrupole and the changes predicted by the dynamo theories. In conclusion

    更新日期:2020-10-11
  • Secular Evolution of Rings around Rotating Triaxial Gravitating Bodies
    Astron. Rep. (IF 1.164) Pub Date : 2020-10-10
    B. P. Kondratyev, V. S. Kornoukhov

    Abstract The problem of the secular evolution of a thin ring around a rapidly rotating triaxial celestial body is formulated and solved. The technology for calculating secular perturbations is based on two formulas: the azimuthally averaged force field of the central body and the mutual energy \({{W}_{{{\text{mut}}}}}\) of this body and a Gaussian ring. With \({{W}_{{{\text{mut}}}}}\) instead of the

    更新日期:2020-10-11
  • Parameter Comparison of Several Types of Pulsars
    Astron. Rep. (IF 1.164) Pub Date : 2020-09-23
    I. F. Malov, H. P. Marozava

    Abstract— We have carried out a comparative analysis of the parameters of two samples of radio pulsars. The first of them is characterized by periods \(P > 2\) s, the second one—by the surface magnetic fields \({{B}_{s}} > 4.4 \times \) 1013 G. The purpose for selecting these values is for the understanding the origin of the difference between normal pulsars and anomalous X-ray pulsars (AXP) and gamma-repeaters

    更新日期:2020-09-23
  • Motion of a Pair of Gravitating Bodies in Dark Energy Presence: Small Deviations from Keplerian Motion
    Astron. Rep. (IF 1.164) Pub Date : 2020-09-23
    A. I. Neishtadt, G. S. Bisnovatyi-Kogan

    Abstract The problem of the motion of two gravitating bodies in the presence of dark energy (DE), considered as a perturbing factor, is investigated. In addition to the orbit precession frequency obtained in previous studies, the correction to the orbital motion frequency was calculated, and the oscillations of the semi-major axis and the eccentricity of the orbit caused by the influence of DE were

    更新日期:2020-09-23
  • Development of Methods for Navigational Referencing of Circumlunar Spacecrafts to the Selenocentric Dynamic Coordinate System
    Astron. Rep. (IF 1.164) Pub Date : 2020-09-23
    A. O. Andreev, Yu. A. Nefedyev, N. Yu. Demina, L. A. Nefediev, N. K. Petrova, A. A. Zagidullin

    Abstract The initial form of present-day space optical observations contain considerable geometrical and brightness distortions. This problem can be solved based on geometrical correction and transformation of reference object coordinates into commonly accepted cartographic projections. In this work, the method of coordinate transformation to the reference selenocentric dynamic system by using a base

    更新日期:2020-09-23
  • Central Field Motion with Perturbing Acceleration Varying According to the Inverse Square Law in the Reference Frame Associated with the Radius Vector
    Astron. Rep. (IF 1.164) Pub Date : 2020-09-23
    T. N. Sannikova, K. V. Kholshevnikov

    Abstract The motion of a point with zero mass under the action of attraction to the central body \(\mathcal{S}\) and perturbing acceleration \({\mathbf{P}}{\kern 1pt} ' = {\mathbf{P}}{\text{/}}{{r}^{2}}\), inversely proportional to the square of the distance to \(\mathcal{S}\), is considered. It is assumed that \({\mathbf{P}}{\kern 1pt} '\) is small in absolute value compared to the main acceleration

    更新日期:2020-09-23
  • Deflecting an Asteroid with a Low-Thrust Tangential Engine to the Orbit
    Astron. Rep. (IF 1.164) Pub Date : 2020-09-23
    K. V. Kholshevnikov, D. V. Milanov, K. I. Os’kina, V. B. Titov

    Abstract In order to solve the problem of deflecting a dangerous asteroid from a collision orbit with the Earth, using a low-thrust engine directed tangentially to the trajectory is considered. The engine can be mounted on the asteroid or on a “gravity tractor.” The purpose of this study is to establish the fundamental possibility of steering away an asteroid to a safe distance over times of approximately

    更新日期:2020-09-23
  • Suggestion for Search of Malononitrile (CH 2 (CN) 2 ) in a Cosmic Object: Potential Spectral Lines
    Astron. Rep. (IF 1.164) Pub Date : 2020-09-23
    M. K. Sharma, M. Sharma, S. Chandra

    Abstract Though accurate laboratory studies of malononitrile (CH2(CN)2), a dinitrile molecule, have been carried out from time to time, and it has large electric dipole moment \(\mu = 3.735\) D, its detection in a cosmic object is still awaited. Because of two equivalent hydrogen atoms, it has ortho and para species. In order to obtain information about some potential spectral lines of malononitrile

    更新日期:2020-09-23
  • Binary Star Population with Common Proper Motion in Gaia DR2
    Astron. Rep. (IF 1.164) Pub Date : 2020-09-23
    S. A. Sapozhnikov, D. A. Kovaleva, O. Yu. Malkov, A. Yu. Sytov

    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 clusters and systems with multiplicity larger than 2 were excluded from consideration. The

    更新日期:2020-09-23
  • Deuterium Fractionation in the Oph-H-MM1 Dense Core of the L1688 Low Mass Star-Forming Region
    Astron. Rep. (IF 1.164) Pub Date : 2020-08-31
    I. V. Petrashkevich, A. F. Punanova, P. Caselli, J. Pineda, A. Pon, R. Friesen

    Abstract Molecular clouds fragment to form dense cores, which are the first stage of star formation. Such objects are cold, with temperature of ~10 K and density of \({{10}^{4}}{-} {{10}^{7}}\) cm–3, with predominance of thermal motions and high deuterium fraction. These objects give us information about the initial conditions of star formation and thus they are very important to understand this process

    更新日期:2020-08-31
  • Impact of the Small-Scale Spatial Distribution of Dust Particles on the Chemical Evolution of the Diffuse Interstellar Medium
    Astron. Rep. (IF 1.164) Pub Date : 2020-08-31
    V. A. Sokolova, A. I. Vasyunin, A. B. Ostrovskii, S. Yu. Parfenov

    Abstract In this work we analyze the effect of gas-dust clumps, possibly formed in the interstellar medium due to instability, described in [10], on the chemical evolution of the diffuse interstellar medium. For this purpose we calculate chemical evolution with common parameters of diffuse interstellar medium (ISM). It is shown that abundances of most observed molecules are higher in a model of the

    更新日期:2020-08-31
  • Probing Modified Gravity with the Structures Maximum Dimensions
    Astron. Rep. (IF 1.164) Pub Date : 2020-08-31
    A. Del Popolo

    Abstract By using an extended spherical collapse model taking into account the effects of shear, vorticity, and dynamical friction we found the relationship between the turnaround radius, \({{R}_{t}}\), and mass, \({{M}_{t}}\), in \(\Lambda \)CDM and dark energy scenarios. We get a more general formula than that usually described in literature, showing a dependence of \({{R}_{t}}\) from shear, vorticity

    更新日期:2020-08-31
  • Solar Gamma-Ray Flares and Activity Complexes
    Astron. Rep. (IF 1.164) Pub Date : 2020-08-31
    V. M. Tomozov, S. A. Yazev, E. S. Isaeva

    Abstract Strong flare events with an extended phase of gamma ray emission from the catalog by Share et al. have been analyzed in order to explain the characteristics of the impulsive and extended phases of such flares and reveal their connection with activity complexes and coronal holes. It is shown that 74% of such events are closely related to activity complexes. It has been qualitatively demonstrated

    更新日期:2020-08-31
  • Diffusion Ionised Gas in the Directions of the Supernova Remnant Kes 79 and Pulsar B1849+00
    Astron. Rep. (IF 1.164) Pub Date : 2020-08-31
    A. V. Pynzar

    Abstract Based on the spatial correlation between the distributions of diffuse ionized gas (DIG) and the HII regions in the Galaxy and using observations of the Galactic background in the H166α line found in literature, we investigated the strong inhomogeneity of the DIG in the direction of longitude 33.5° near the Galaxy plane, where objects located at close angular distances from each other have

    更新日期:2020-08-31
  • Solar System Encounters with Open Star Clusters
    Astron. Rep. (IF 1.164) Pub Date : 2020-08-31
    M. D. Sizova, S. V. Vereshchagin, B. M. Shustov, N. V. Chupina

    Abstract 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 comet motion in the outer regions of the Oort

    更新日期:2020-08-31
  • Radio Emission of the Combined Supernova Remnant 3C396 (G39.2-0.3)
    Astron. Rep. (IF 1.164) Pub Date : 2020-08-31
    V. P. Ivanov, A. V. Ipatov, I. A. Rakhimov, T. S. Andreeva

    Abstract Using the RT-32 radio telescope of the “Svetloe” IAA RAS observatory in 2017–2018, the flux density measurements of the combined (composite) supernova remnant (SNR) 3С396 (G39.2-0.3) at frequencies of 4840 and 8450 MHz are presented. The data obtained demonstrate source variability. Published data were used to determine the 3C396 flux density in 1962–2008 based on a comparison of the intensities

    更新日期:2020-08-31
  • Variability of the Blazar B1308+326 in 2011–2018
    Astron. Rep. (IF 1.164) Pub Date : 2020-08-31
    V. A. Hagen-Thorn, D. A. Morozova, E. I. Hagen-Thorn, S. S. Savchenko, I. S. Troitsky, L. V. Shaliapina, E. V. Volkov

    Abstract— The monitoring results of the blazar B1308+326 in the optical and radio bands in 2011–2018 are presented and analyzed. An optical flare of the object associated with the passage of revealed superluminal components through the radio core, coinciding in time with a γ-ray outburst, as well as outbursts at 43 GHz, were detected. The photometric variability is explained by a variable component

    更新日期:2020-08-31
  • Quasi-Resonant States of Hydrogen Gas
    Astron. Rep. (IF 1.164) Pub Date : 2020-08-31
    V. P. Grinin, N. A. Katysheva, T. A. Ermolaeva, D. V. Dmitriev

    Abstract The article considers the poorly studied states of hydrogen gas (called here “quasi-resonant”) with anomalously high intensity ratios of the lines in the Balmer series, \(I({{{\text{H}}}_{\alpha }}){\text{/}}I({{{\text{H}}}_{\beta }})\). It is shown that such states arise in the case of large optical thicknesses of the emitting gas occurring at the frequencies of the Balmer lines, when the

    更新日期:2020-08-31
  • Multiperiodicity in the Orbital Period Variations of the Eclipsing Binary System Z Per
    Astron. Rep. (IF 1.164) Pub Date : 2020-07-17
    A. I. Khaliullina

    Abstract The variations in the orbital period of the eclipsing binary system Z Per have been analyzed. It has been shown that the variations in the period can be represented as a superposition of the secular decrease in the period at a rate of 1.61 × 10–6 days/year and its three cyclic variations with periods of 22.6, 37.9, and 62.4 years. Z Per is most likely a quadruple system with periods of additional

    更新日期:2020-07-17
  • Possible New Envelope Types of Hot Jupiters
    Astron. Rep. (IF 1.164) Pub Date : 2020-07-17
    A. G. Zhilkin, D. V. Bisikalo

    Abstract—For the case of the sub-Alfvén regime of the stellar wind flyby around the planet, the flow structure in the vicinity of a hot Jupiter have been studied by three-dimensional numerical simulation. As an example, the hot Jupiter HD 209458b was considered. The planet’s magnetic moment was set equal to 10% of the magnetic moment of Jupiter. The average magnetic field at the parent star’s surface

    更新日期:2020-07-17
  • Classification of Young Pulsars and Empirical Evolution of Regular Braking Index
    Astron. Rep. (IF 1.164) Pub Date : 2020-07-17
    A. P. Glushak

    Abstract—The distribution of young pulsars in the log(dP/dt)–log(tc) diagram that have a characteristic age tc < ~5 × 106 yr and a period derivative dP/dt > ~10–16 is analyzed. Six clusters-stripes are revealed for the first time, along which the long-term evolution tracks of individual pulsars pass. The mean track in a stripe corresponds to the long-term regular evolution for a typical pulsar of this

    更新日期:2020-07-17
  • Exoplanet Transients: Possible Variations in the Limb-Darkening Coefficients of Eclipsed Stars at Short Time Intervals
    Astron. Rep. (IF 1.164) Pub Date : 2020-07-17
    M. K. Abubekerov, N. Yu. Gostev

    Abstract The interpretation of high-precision transit light curves of binary systems with exoplanets Kepler-5b, Kepler-6b, and Kepler-7b is performed for three different epochs. It has been demonstrated that the values of the stellar limb-darkening coefficients differ significantly for each epoch, while the geometric parameters for each epoch agree well with each other within the error margin. It is

    更新日期:2020-07-17
  • Black Hole Shadow Observations with Space-Ground Interferometers
    Astron. Rep. (IF 1.164) Pub Date : 2020-07-17
    E. V. Mikheeva, S. V. Repin, V. N. Lukash

    Abstract The study explores black hole (BH) shadow images which can be restored by data processing and image recovery procedures during space Very Large Baseline Interferometry (VLBI) missions in the future. For Kerr BHs with masses and coordinates of SgrA*, M87*, and M31*, all illuminated by a light source behind them, three kinds of observation are considered: the ground-based interferometer (similar

    更新日期:2020-07-17
  • Evolution of OH and H 2 O Maser Emission in the Active Star Formation Region NGC 2071
    Astron. Rep. (IF 1.164) Pub Date : 2020-07-17
    N. T. Ashimbaeva, P. Colom, V. V. Krasnov, E. E. Lekht, M. I. Pashchenko, G. M. Rudnitskii, A. M. Tolmachev

    Abstract We present the observation results of the star forming region NGC 2071 in the 1.35-cm H2O line and 18-cm OH lines obtained with the 22-m radio telescope in Pushchino (Russia) and the large radio telescope in Nançay (France), respectively. The catalog of H2O maser emission spectra from December 2010 to January 2020 is given. The total flux variability for the entire monitoring period (1979–2020)

    更新日期:2020-07-17
  • Oxygen Atom Escape from the Martian Atmosphere during Proton Auroral Events
    Astron. Rep. (IF 1.164) Pub Date : 2020-07-17
    V. I. Shematovich, E. S. Kalinicheva

    Abstract 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 km is accompanied by the momentum and energy transfer in

    更新日期:2020-07-17
  • On the Dark Matter Profile Mass Dependence
    Astron. Rep. (IF 1.164) Pub Date : 2020-07-17
    A. Del Popolo

    Abstract In this paper, we check the claim of dependence of the halo density profile on the ratio between stellar and halo mass. Namely, we want to continue the work done in a previous paper by Del Popolo (2015), to see to what extent the SN feedback scenario is able to describe the inner structure of galaxies, employing more sophisticated statistical tools than those indicated in the quoted paper

    更新日期:2020-07-17
  • Principles of Pulsar Space Navigation
    Astron. Rep. (IF 1.164) Pub Date : 2020-06-16
    A. E. Rodin, V. V. Oreshko, V. A. Potapov, M. S. Pshirkov, M. V. Sazhin

    Abstract The paper considers the principles of space navigation using pulsars observed in the radio range. The requirements for receiving equipment are outlined, a recommended pulsar list is given, and an algorithm for determining the position of a spacecraft in barycentric coordinates and calculating corrections to the onboard time scale is described.

    更新日期:2020-06-16
  • Three-Dimensional Numerical Simulation of a Flow Structure in the Asynchronous Polar CD Ind in the Approximation of an Offset Dipole Magnetic Field of a White Dwarf
    Astron. Rep. (IF 1.164) Pub Date : 2020-06-16
    A. V. Sobolev, A. G. Zhilkin, D. V. Bisikalo, D. A. H. Buckley

    The flow structure in the asynchronous polar CD Ind was investigated in the approximation of an offset dipole. Computation results made it possible to identify such system features as the drift of hot spots over the white dwarf surface, the flow structure dependence on the phase of the beat period, and the magnetic pole switching. To study the flow structure, a three-dimensional numerical MHD model

    更新日期:2020-06-16
  • Rapid Polarized Emission Variability of Blazar S5 0716+714 in Optical Range
    Astron. Rep. (IF 1.164) Pub Date : 2020-06-16
    V. S. Bychkova, N. S. Kardashev, K. L. Maslennikov, V. L. Plokhotnichenko, G. M. Beskin, S. V. Karpov

    Abstract— The results of polarimetric observations of blazar S5 0716+714, carried out with the 6-meter BTA telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences, are presented. The polarized emission microvariability of blazar S5 0716+714 was observed in the R band with an initial time resolution of 3–5 seconds. Exposures were integrated at 1-minute intervals with a

    更新日期:2020-06-16
  • Restructuring of the Solar Magnetic Fields and Flare Activity Centers in Cycle 24
    Astron. Rep. (IF 1.164) Pub Date : 2020-06-16
    A. V. Borovik, A. V. Mordvinov, E. M. Golubeva, A. A. Zhdanov

    Abstract The development of the solar magnetic activity in cycle 24 has been analyzed. It has been shown that the significant north–south asymmetry of magnetic activity was accompanied by the asynchronous reorganization of solar magnetic fields in the northern and southern hemispheres. The formation of unipolar magnetic regions after the decay of activity centers has been studied. The meridional transport

    更新日期:2020-06-16
  • Detection of Five New Pulsars with the BSA LPI Radio Telescope
    Astron. Rep. (IF 1.164) Pub Date : 2020-06-16
    S. A. Tyul’bashev, M. A. Kitaeva, V. S. Tyul’bashev, V. M. Malofeev, G. E. Tyul’basheva

    Abstract During five years of daily observations, the search for new pulsars using the BSA LPI radio telescope in 96 spatial beams covering 17 000 square degrees was conducted. Five new pulsars were identified. Candidate pulsars were selected in summed power spectra. A noise generator was used to renormalize data and total the power spectra for individual directions correctly. As a result, the sensitivity

    更新日期:2020-06-16
  • Mutual Gravitational Energy of Gaussian Rings and the Problem of Perturbations in Celestial Mechanics
    Astron. Rep. (IF 1.164) Pub Date : 2020-06-05
    B. P. Kondratyev, V. S. Kornoukhov

    Abstract A new approach to the study of long-period and secular perturbations in celestial mechanics is developed. In contrast to the traditional use of the apparatus of the perturbing Lagrange function, we rely on the mutual potential energy of elliptic Gaussian rings. This approach is important due to the fact that instead of averaging the expression for the perturbing Lagrange function obtained

    更新日期:2020-06-05
  • Relativistic Reductions in High-Precision Measurements of the Earth’s Global Gravity Field Using a Multipair Constellation
    Astron. Rep. (IF 1.164) Pub Date : 2020-06-05
    V. K. Milyukov, I. Yu. Vlasov, M. V. Sazhin, O. S. Sazhina, V. N. Sementsov

    Abstract— The theory of relativistic reductions for future challenges of space gravimetry with target accuracy of up to 1 picometer is developed in this paper.

    更新日期:2020-06-05
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