Kinematics and Physics of Celestial Bodies最新文献

{"title":"Radio Properties of the Low-Redshift Isolated Galaxies with Active Nuclei","authors":"N. G. Pulatova,&nbsp;I. B. Vavilova,&nbsp;A. A. Vasylenko,&nbsp;O. M. Ulyanov","doi":"10.3103/S088459132302006X","DOIUrl":"10.3103/S088459132302006X","url":null,"abstract":"<p>The properties of 61 isolated galaxies with active nuclei (isolated AGNs) in the radio frequency range at redshifts <i>z</i> &lt; 0.05 have been studied. The sample is obtained by cross-matching of the 2MIG catalog (2MASS catalog of isolated galaxies based on the 2MASS) with the Véron-Cetty catalog of quasars/AGNs. The sample is limited to a stellar magnitude of 4^<i>m</i> &lt; <i>K</i>_s ≤ 12^<i>m</i>, a radial velocity of <i>V</i>_<i>r</i> &lt; 15 000 km/s, and the distance to the nearest large satellite galaxy. These limitations indicate that the isolated AGNs have not collided with other galaxies in at least 3 billion years, and the observed activity of their nuclei is due only to physical processes occurring in the torus–accretion disk–nuclear region–supermassive black hole system. This study systematized the radio parameters of isolated AGNs by using data from various databases and the archive of terrestrial and space telescopes. Such characteristics are necessary for the further comparative study of physical properties of regions with active star formation and the active nuclei of these galaxies with the properties that manifest themselves when observing other spectral ranges. As a result, the radio flux densities available from the databases at a frequency of 1.4 or 5 GHz for isolated AGNs from the 2MIG catalog are given. Among the 61 galaxies of the sample, flux densities at 1.4 GHz have been found for 51 galaxies. These values are in the range of 3–20 mJy for most isolated AGNs and in the range of 50–200 mJy for two galaxies PGC35009 and NGC6951, while two galaxies ESO483-009 and ESO097-013 have spectral flux densities of 352 and 1200 mJy, respectively. The flux densities of ten isolated AGNs are less than 3 mJy. Radio flux densities of NGC0157 are not related to the position of this galaxy. Ratio <i>R</i> of the spectral flux densities in the radio frequency range to those in the optical bands have been calculated. Since the flux densities at 5 GHz are measured only for eight isolated AGNs, the required values of spectral flux densities at 5 GHz on the basis of relationship <i>S</i>_ν ∝ ν^–α for galaxies of the Seyfert type have been calculated by using the radio flux density values at 1.4 GHz and assuming that the spectral index is equal to α = 0.7. The radio fluxes densities at 5 GHz are lower than 3 mJy for 27 isolated AGNs, are in the range of 4–15 mJy for 15 AGNs, and in the range of 15–55 mJy for seven AGNs, while two galaxies ESO097-013 and ESO483-009 have radio fluxes densities of 304 and 132 mJy, respectively. We have found that 51 isolated AGNs are radio quiet sources (<i>R</i> &lt; 10), the radio properties of nine objects are absent, and ESO483-009 is a radio loud galaxy (<i>R</i> = 20.72, Sy3/LINER, and SAB00 pec). We propose the observational methods to determine the flux densities of radio quite isolated AGNs. In conclusion, the systematization of the propert","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"39 2","pages":"98 - 115"},"PeriodicalIF":0.5,"publicationDate":"2023-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4942620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ionospheric Effects of the Kamchatka Meteoroid: Results of GPS Observations","authors":"Y. Luo,&nbsp;L. F. Chernogor","doi":"10.3103/S0884591323020058","DOIUrl":"10.3103/S0884591323020058","url":null,"abstract":"<p>The most important event in astronomy and celestial physics in the early 21st century is the fall of the Chelyabinsk meteoroid with a kinetic energy of nearly 440 kt TNT. Such an event occurs once every 65 years on average. The effects of this celestial body are considered in more than 200 scientific papers. At the same time, less than 25 papers are devoted to the fall of another large meteoroid called the Kamchatka meteoroid on December 18, 2018, at 23:48:20 UT (Universal time). Meanwhile, the parameters of this meteoroid are quite unique. The velocity components are <i>v</i>_<i>x</i> = 6.3, <i>v</i>_<i>y</i> = –3, and <i>v</i>_<i>z</i> = –31.2 km/s, and the velocity magnitude was 32 km/s. The total optical radiated energy was <i>E</i>_r = 1.3 × 10¹⁴ J (31 kt of TNT), the fireball explosion altitude was <i>z</i>_<i>r</i> = 26 km, and the coordinates are 56.9° N, 172.4° E. The angle of entry into the atmosphere with respect to the horizon was close to 68.6°. The meteoroid had the initial kinetic energy of 173 kt of TNT, the mass of 1.41 kt, and the size of nearly 9.4 m. The fall of such bodies occurs at a frequency of once every 30 years. It is of interest to perform the further study of its ionospheric effects and compare the results measured by ground-based and satellite methods with each other. The objective of this study is to analyze the results of GPS observations for the ionospheric effects to compare them with the results measured by the method of ground-based oblique incidence sounding of the ionosphere. To observe the ionospheric disturbances following the fall of the Kamchatka meteoroid, an AC60 receiving station (geographic coordinates, 53° N, 173° E) located at a distance of 450 km from the Kamchatka meteoroid explosion site and six GPS satellites (PRN02, PRN05, PRN07, PRN09, PRN29, and PRN30) were used. The principal results of these studies are the following. GPS technologies were used to estimate the delay times of ionospheric response to the Kamchatka meteoroid explosion, the horizontal propagation velocities of disturbances (504–520 m/s) and their periods (11–18 min), durations (22–35 min), wavelengths (333–530 km), and the relative amplitudes of electron density disturbances (3–4%). The estimate obtained for the relative amplitudes of wave disturbances in the electron density by the ground-based and satellite methods have proven to be close to each other (3–4%). Their periods also have close values (10–15 min). The ground-based and satellite methods also revealed the wave disturbances associated with both atmospheric gravity and seismic waves.</p>","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"39 2","pages":"71 - 77"},"PeriodicalIF":0.5,"publicationDate":"2023-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4942627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variations in the Mid-Latitude Ionosphere Parameters over Ukraine during the Very Moderate Magnetic Storm on December 18, 2019","authors":"S. V. Katsko,&nbsp;L. Ya. Emelyanov","doi":"10.3103/S0884591323020034","DOIUrl":"10.3103/S0884591323020034","url":null,"abstract":"<p>Multiyear researches show that weak and moderate magnetic storms may induce considerable and unpredictable changes in the ionosphere state. The problems of predicting the ionosphere response in a certain region to space weather changes currently remain topical since the physical processes occurring in the ionospheric plasma are variable and complicated. Particular interest is attracted by ionospheric disturbances with variable phases at middle latitudes and their propagation to low latitudes and the occurrence of strong ionospheric storms as a result of moderate or weak magnetic storms. The objective of this study is to perform the experimental studies of variations in the ionospheric plasma parameters over Ukraine during the very moderate magnetic storm on December 18, 2019. The study was carried out by using the incoherent scatter of radio waves as providing the most complete diagnostic capabilities and the vertical sounding method. Observations were performed in the Ionospheric Observatory of the Institute of Ionosphere (National Academy of Sciences of Ukraine, Ministry of Education and Science of Ukraine, Kharkiv) with an incoherent scatter radar. The critical frequencies were measured with a portable ionosonde. In addition, the geophysical information about the space weather and magnetosphere parameters was used. The ionosphere response to the geospace storm on December 18, 2019, over Kharkiv was analyzed. The very moderate magnetic storm (<i>K</i>_p = 4) was established to induce positive ionospheric disturbance. An increase in the critical frequency (up to 1.6 times) and a corresponding increase in the ionospheric <i>F</i>2 peak electron density (up to 2.6 times) was accompanied by a sequence of changes in the variations of principal ionospheric plasma parameters, such as the <i>F</i>2 layer peak height (a decrease by 30 km), the electron density throughout the entire range of studied altitudes (200–450 km), the electron and ion temperatures, and the vertical ionospheric plasma velocity component (with a decrease in the downward plasma drift velocity <i>V</i>_z at the noon after the magnetic storm began with further velocity recovery, the occurrence of fluctuations in the variations <i>V</i>_z with a quasi-period of 1 h 50 min at 15:40 UT (Universal Time) at altitudes of 360–420 km, and weakening of the evening extremum effect in the <i>V</i>_z variations and a maximum decrease in the velocity to 40–70 m/s at these altitudes). A substantiation was given for the following mechanism of the formation of a positive ionospheric storm: the downward plasma drift is weakened in the mid-latitude ionosphere during the winter daylight due to the fact that normal circulation is weakened by reverse storm-induced circulation. The very moderate magnetic storm on December 18, 2019, induced appreciable changes in the ionospheric plasma parameters throughout the entire range of studied altitudes. The measured data ","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"39 2","pages":"78 - 89"},"PeriodicalIF":0.5,"publicationDate":"2023-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4948636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radiometric On-Orbit Calibration of the Aerosol-UA Mission Scanning Polarimeter: Technique, Design Elements, and Illumination Angles","authors":"I. I. Syniavskyi,&nbsp;V. O. Danylevsky,&nbsp;Y. A. Oberemok,&nbsp;Y. S. Ivanov,&nbsp;R. S. Osypenko,&nbsp;M. G. Sosonkin,&nbsp;G. P. Milinevsky,&nbsp;I. V. Fesianov","doi":"10.3103/S0884591323010075","DOIUrl":"10.3103/S0884591323010075","url":null,"abstract":"<p>The concept of a device for the radiometric calibration of photometers or polarimeters on the Earth orbit using the Sun is considered. The shortcomings and advantages for the designing and materials of the key elements are analyzed. The illumination conditions are determined for the working element of the radiometric calibration assembly of the ScanPol scanning polarimeter aboard the YuzhSat satellite platform for different configurations in different orbit locations. The satellite orbit sections where solar illumination is optimal for the working element of this assembly from the viewpoint of the relation between the incidence and observation angles and minimization of the light caused by reflection from the Earth surface, atmosphere, ScanPol structure elements, and satellite platform are specified. The obtained results are planned for use in the development of an optimal design for the ScanPol radiometric calibration assembly to provide a necessary radiometric measurements precision during the Aerosol-UA space mission.</p>","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"39 1","pages":"49 - 69"},"PeriodicalIF":0.5,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4799614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compact Galaxies with Active Star Formation from the SDSS Data Release 16: Star-Formation Rates Based on the Luminosities of Forbidden Emission Lines in the Optical Range","authors":"I. Y. Izotova,&nbsp;Y. I. Izotov","doi":"10.3103/S0884591323010038","DOIUrl":"10.3103/S0884591323010038","url":null,"abstract":"<p>We obtained equations for determining the star-formation rate in local compact star-forming galaxies from the SDSS Data Release 16 using luminosities of the forbidden emission lines [O II] λ 372.7 nm, [Ne III] λ 386.8 nm, [O III] λ 495.9 nm, and [O III] λ 500.7 nm and their combinations. The equations are based on the assumption that the star-formation rates, determined from the luminosity of the forbidden lines and H_β emission lines, are equal. This approach is especially useful because the observation of H_β emission is not always possible. For example, in galaxies with redshift <i>z</i> &gt; 1, this line goes beyond the optical range, and the [O II] λ 372.7 nm line, the [Ne III] λ 386.8 nm line, or their combination can be used instead. On the other hand, in many studies of faint objects using low-resolution spectra, the H_β line merges with the stronger [O III] λ 495.9 nm and [O III] λ 500.7 nm lines. In these cases, [O III] lines and their combination can be used to determine the rate of star formation. The resulting equations can be applied to compact star-forming galaxies in a wide range of redshifts.</p>","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"39 1","pages":"24 - 32"},"PeriodicalIF":0.5,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4797877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"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","authors":"M. Ishchenko,&nbsp;M. Sobolenko,&nbsp;P. Berczik,&nbsp;T. Panamarev","doi":"10.3103/S0884591323010026","DOIUrl":"10.3103/S0884591323010026","url":null,"abstract":"<p>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 passages (“collisions” herein) of SGCs with respect to each other and the Galactic center (GC) in the Galaxy undergoing dynamic changes in the past. To reproduce the dynamics of the Galaxy in time, five of the 54 potentials previously selected from the IllustrisTNG-100 large-scale cosmological database, which are similar in their characteristics (masses and dimensions of the disk and halo) to the current physical parameters of the Milky Way, are used. With these time-varying potentials, we have reproduced the orbital trajectories of 143 SGCs 10 billion years back in time using our original φ-GPU high-order N-body parallel dynamic computer code. Each SGC was treated as a single physical particle with the assigned position and velocity of the cluster center from the Gaia DR2 observations. For each of the potentials, 1000 initial conditions were generated with randomized initial velocities of SGCs within the errors of the observational data. In this study, we consider close passages to be passages with a relative distance of less than 100 pc and a relative speed of less than 250 km s^–1. Clusters that pass at longer distances and/or with higher velocities do not have a substantial dynamic effect on the orbits of SGC. In our opinion, the largest changes in the orbits of clusters can be caused by clusters that pass with low velocities at distances smaller than several fold (for example, fourfold) the sum of the radii of the cluster half-masses. Therefore, the authors regard such close passages separately (for brevity, we will call such passages “collisions”). To select clusters that pass at close distances from the GC, the following criterion is applied based only on the relative distance: it must be less than 100 pc. Applying the above criteria, the authors obtained statistically significant rates of close passages of SGCs with respect to each other and to the GC. It has been determined that SGCs during their evolution have approximately ten intersecting trajectories with each other on the average and approximately three to four close passages near the GC in 1 billion years at a distance of 50 pc for each of the chosen potentials.</p>","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"39 1","pages":"33 - 44"},"PeriodicalIF":0.5,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4797444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variation of the H Component of Geomagnetic Field: Relationship to the Ring and Field Aligned Currents","authors":"Sabin Gautam,&nbsp;Sarup Khadka Saurav,&nbsp;Binod Adhikari,&nbsp;Santosh Sapkota,&nbsp;Parashu Ram Poudel,&nbsp;Roshan Kumar Mishra,&nbsp;Chhabi Kumar Shrestha","doi":"10.3103/S0884591323010063","DOIUrl":"10.3103/S0884591323010063","url":null,"abstract":"<p>Disturbance of equatorial ring current during the geomagnetic storm has dominant effect on geomagnetic field. The short term irregular variation on geomagnetic field is characterized by interaction of solar-wind magnetic field and Earth’s magnetosphere, which develops time varying current in magnetosphere and ionosphere. This study represents the irregular variation on H component of Earth’s magnetic field during three intense geomagnetic storm events. Among the five selected stations, four are at low-latitude and remaining one is at middle latitude. All the stations recorded the maximum depression on H component during the main phase of storm but sudden storm commencements (SSCs) event before initial phase caused slight increase in magnitude. In each of the event, low-latitude stations recorded large perturbation on magnetic field as compared to the middle latitude station. This result supports the intensification of ring current as initiated by the transfer of plasma and energy through interplanetary coronal mass ejections (ICMEs) and finally causes falling off of H component. Kakadu station (southern latitude) showed maximum value of Δ<i>H</i> in second and third event, this result keeps up that mostly southern hemisphere station measures large decline on <i>H</i> component during storm time. The calculated value of ring current and field aligned current (FAC) showed extreme negative correlation with Δ<i>H</i>. This unique result reveals that ring current is not only a factor that cause disturbance on horizontal component of Earth’s magnetic field but FAC also has considerable effect.</p>","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"39 1","pages":"10 - 23"},"PeriodicalIF":0.5,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4797866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early Forecast of a Maximum in the 25th Cycle of Solar Activity","authors":"V. G. Lozitsky,&nbsp;V. M. Efimenko","doi":"10.3103/S088459132301004X","DOIUrl":"10.3103/S088459132301004X","url":null,"abstract":"<p>The statistical relation between the rate of increase in the number of sunspots at the initial phase of the growth curve (from 20th to 29th cycle months) and the cycle amplitude is considered on the basis of data on the 24 previous solar cycles. It has been concluded that the maximum smoothed number of sunspots for the 25th cycle must be equal to <i>W</i>_max(25) ≈ 206 in the case when the growth phase is monotonical and <i>W</i>_max(25) ≈ 160 in the case of its nonmonotonical character with a split top as in the 24th cycle. Both cases correspond to a moderate solar cycle obeying the Gnevyshev–Ohl rule. At such current cycle parameters, there are no signs of a coming deep secular cycle minimum in the middle of the 21st century.</p>","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"39 1","pages":"45 - 48"},"PeriodicalIF":0.5,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4802355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Resonance Electromagnetic Effect of the Kamchatka Meteoroid","authors":"Y. Luo,&nbsp;L. F. Chernogor","doi":"10.3103/S0884591323010051","DOIUrl":"10.3103/S0884591323010051","url":null,"abstract":"<p>A large meteoroid entered the terrestrial atmosphere and exploded at an altitude of 26 km between the Kamchatka Peninsula and Alaska (geographic coordinates 56.9° N, 172.4° E) over the Bering Sea at 23:48:20 UT on December 18, 2018. The meteoroid has been named the Kamchatka (or Bering Sea) meteoroid. Its basic parameters are as follows: calculated total impact energy 173 kt of TNT, total optical radiated energy 1.3 × 10¹⁴ J, mass 1.41 kt, speed 32 km/s, size 9.4 m, and the trajectory directed at an angle of 68.6° with respect to the horizon. The entry of the Kamchatka meteoroid into the atmosphere was accompanied by the generation of a transient resonance electromagnetic signal in the 25–35 mHz band observable in the vicinity of the meteoroid explosion and in the magnetically conjugate region. Oscillations with amplitudes of 0.2–0.8 nT were observed over a 7-min interval. This study is aimed at analyzing the observations of the resonance electromagnetic effect from the Kamchatka meteoroid and discussing a mechanism for this effect. The resonance effect in the Earth’s magnetic field is analyzed using data with a time resolution of 1 s and an amplitude resolution of 1 nT from the database collected by the Intermagnet magnetometer network of magnetic observatories. The distance between the site of the meteoroid explosion and the magnetic observatories ranges from 1000 to 5000 km in the Northern Hemisphere and from 9010 to 12 425 km in the Southern Hemisphere. It is established that the only feasible mechanism is associated with the magnetic field displacement in the magnetosphere by the explosive impact of the celestial body, whereas only a negligibly small part of the meteoroid’s energy is spent on the generation of magnetic field perturbations. The meteoroid’s energy losses are similar to the losses in the reactive components of the radio frequency circuits, i.e., they return into the system. The oscillations cease after the meteoroid flies by, and the system returns into the initial state. The main results are summarized as follows. The resonance electromagnetic oscillations arose at 13 and 3 min prior to the Kamchatka meteoroid explosion. The duration of each observed perturbation is close to 7 min. The parameters of the quasi-periodic perturbations are similar to the parameters of magnetic Pc3 pulsations; however, they occured in the <i>Y</i> component of the magnetic field rather than in the <i>X</i> component of the magnetic field. Their observed periods are in the range of 33–36 s, and the amplitudes are in the range of 0.4–0.9 nT. Similar resonance oscillations were also recorded in the magnetically conjugate region. A mechanism for generating the resonance oscillations is proposed. The essence of the mechanism is that the meteoroid explosively impacts the magnetosphere and deforms the magnetic field lines that begin to oscillate at their eigenfrequencies. Depending on the McIlwain <i>L</i>-shell, the calculated period of osc","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"39 1","pages":"1 - 9"},"PeriodicalIF":0.5,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4801920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photometric Variability of BL Lacertae and 1ES 1426+428 Blazars in the Optical and Gamma Ranges","authors":"І. O. Izviekova,&nbsp;V. A. Ponomarenko,&nbsp;N. G. Pulatova,&nbsp;V. V. Vasylenko,&nbsp;A. O. Simon","doi":"10.3103/S0884591322060034","DOIUrl":"10.3103/S0884591322060034","url":null,"abstract":"<div><p>The results of photometric observations of two bright blazars of the northern hemisphere, namely, BL Lacertae and 1ES 1426+428, during 2018–2020 through <i>BVRI</i> filters of the Johnson/Bessel system are given. The observations were performed with the two telescopes: AZT-8 of observation station Lisnyky of the Astronomical Observatory of the Taras Shevchenko National University of Kyiv (Kyiv oblast, Ukraine) and Zeiss-600 of high-altitude observatory Peak Terskol of the International Center for Astronomical, Medical, and Ecological Research (IC AMER) of the National Academy of Sciences of Ukraine. In total, more than sixty nights of observations were recorded and processed. The main goals have been in performing a cross-matching analysis of blazar light curves in <i>BVRI</i> bands to detect the short-term variability (STV) and long-term variability (LTV) and to investigate the chromaticity of color parameters. For both objects, fluctuations of brightness up to 1^<i>m</i> in 2018–2020 were recorded in the <i>BVRI</i> bands of the Johnson/Bessel system with a total error of 0.03^<i>m</i>–0.1^<i>m</i>. The intraday variability (IDV) was revealed for BL Lacertae November 17/November 18, 2018. During the calculations of the color indices, the trend of bluish color with an increase in the brightness (bluer-when-brighter, BWB) was found. For BL Lacertae, the LTV was reliably detected by using different pairs of filters. Also, the BWB trend with an average correlation (over 0.5) was recorded for 1ES 1426+428. The presence of such fluctuations in the color of blazars was due to the synchrotron radiation of the jet. The revealed partial correlation of variations in brightness with low time resolution (more than a week) between the photometric optical observations and the data of the Fermi gamma-ray telescope in 2018–2020 require additional research.</p></div>","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"38 6","pages":"328 - 339"},"PeriodicalIF":0.5,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4650241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}