Pub Date : 2024-07-31DOI: 10.1134/s1990341323600424
S. A. Potanin, E. A. Kopylov, A. D. Savvin
Abstract
A differential image motion monitor (DIMM) has been developed and manufactured to study atmospheric seeing. The monitor is made in a lightweight field version and can operate without a telescope, as has always been the case before. Two apertures are made using 70-mm lenses with a focal distance of 900 mm. The distance between the aperture axes is 300 mm. The images from the apertures are combined in the plane of a single CMOS camera operating at up to 314 frames per second speed with low reading noise of about (3e^{-}). The device also includes a (3^{circ}!times!3^{circ}) field of view viewer for pointing at a star. The monitor proved to work successfully during several astroclimate study expeditions. The monitor data were verified by comparing them with the results of atmospheric seeing measurements at the 2.5 meter telescope of the Caucasian Mountain Observatory.
{"title":"Mobile Differential Image Motion Monitor for Astroclimate Research","authors":"S. A. Potanin, E. A. Kopylov, A. D. Savvin","doi":"10.1134/s1990341323600424","DOIUrl":"https://doi.org/10.1134/s1990341323600424","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>A differential image motion monitor (DIMM) has been developed and manufactured to study atmospheric seeing. The monitor is made in a lightweight field version and can operate without a telescope, as has always been the case before. Two apertures are made using 70-mm lenses with a focal distance of 900 mm. The distance between the aperture axes is 300 mm. The images from the apertures are combined in the plane of a single CMOS camera operating at up to 314 frames per second speed with low reading noise of about <span>(3e^{-})</span>. The device also includes a <span>(3^{circ}!times!3^{circ})</span> field of view viewer for pointing at a star. The monitor proved to work successfully during several astroclimate study expeditions. The monitor data were verified by comparing them with the results of atmospheric seeing measurements at the 2.5 meter telescope of the Caucasian Mountain Observatory.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867897","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}
Pub Date : 2024-07-31DOI: 10.1134/s1990341324600467
V. A. Stolyarov, Y. Y. Balega, M. G. Mingaliev, Y. V. Sotnikova, V. F. Vdovin, A. A. Gunbina, D. E. Kukushkin, M. A. Tarasov, M. Y. Fominsky, A. M. Chekushkin, V. S. Edelman, R. A. Yusupov
Abstract
The article discusses the prospects for developing the observational base at the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS) for astrophysical research in the millimeter-wave range. As a first step, a project is proposed to create a set of sub-terahertz receiving equipment to operate at the optical BTA telescope. Additionally, the possibility of installing a new instrument to operate in the frequency range of up to 230 GHz ((lambda=1.3) mm) at the Upper Research Site of SAO RAS is considered. Technical and operational characteristics of the instrument, site selection for the installation of a fully steerable millimeter-wave antenna, statistics of meteorological data and atmospheric absorption are discussed. A list of potential scientific tasks addressed by instruments of this class is provided.
{"title":"Prospects of Millimeter Astronomy Development at the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS)","authors":"V. A. Stolyarov, Y. Y. Balega, M. G. Mingaliev, Y. V. Sotnikova, V. F. Vdovin, A. A. Gunbina, D. E. Kukushkin, M. A. Tarasov, M. Y. Fominsky, A. M. Chekushkin, V. S. Edelman, R. A. Yusupov","doi":"10.1134/s1990341324600467","DOIUrl":"https://doi.org/10.1134/s1990341324600467","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The article discusses the prospects for developing the observational base at the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS) for astrophysical research in the millimeter-wave range. As a first step, a project is proposed to create a set of sub-terahertz receiving equipment to operate at the optical BTA telescope. Additionally, the possibility of installing a new instrument to operate in the frequency range of up to 230 GHz (<span>(lambda=1.3)</span> mm) at the Upper Research Site of SAO RAS is considered. Technical and operational characteristics of the instrument, site selection for the installation of a fully steerable millimeter-wave antenna, statistics of meteorological data and atmospheric absorption are discussed. A list of potential scientific tasks addressed by instruments of this class is provided.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867773","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}
Pub Date : 2024-07-31DOI: 10.1134/s1990341324700275
D. Yu. Tsvetkov, V. P. Goransky, E. A. Barsukova, A. F. Valeev, N. N. Pavlyuk, A. V. Dodin, N. I. Shatsky, S. A. Potanin, N. P. Ikonnikova, M. A. Burlak, A. A. Belinsky, V. A. Echeistov, A. S. Vinokurov, A. N. Sarkisyan, A. V. Zharova
Abstract
The results of photometric and spectroscopic observations of supernova SN 2022prv carried out with six telescopes including the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences and the 2.5-m telescope of the Caucasus Mountain Observatory of SAI MSU are presented. The dates and magnitudes at the brightness maximum and the parameters of the light curves are determined. The photometric evolution of SN 2022prv is characterized by a constant decrease in brightness after the maximum at a rate quite high for a type II supernovae. Approximately 55 days after the maximum, the rate of the decrease in brightness increased. The maximum luminosity has reached (M_{V}=-18overset{textrm{m}}{.}1) which is higher than average for SN II. In the pre-maximum spectra, high-excitation emission lines were observed characteristic of the ionization of the circumstellar matter by a burst during the shock wave emergence onto the surface of the star. However, approximately 20 days after the maximum, the spectrum did not differ from that typical of SN II. The rate of the envelope expansion at this stage was about 3500 km s({}^{-1}) which is a little smaller than average for SN II values.
摘要 介绍了利用六台望远镜（包括俄罗斯科学院特别天体物理观测台的 6 米望远镜和莫斯科大学高加索山观测台的 2.5 米望远镜）对超新星 SN 2022prv 进行光度和光谱观测的结果。确定了亮度最大值的日期和星等，以及光变曲线的参数。SN 2022prv 的光度演化特点是在亮度最大值之后亮度持续下降，下降速率对于 II 型超新星来说相当高。在达到最大值后大约55天，亮度下降的速度加快了。最大光度达到了(M_{V}=-18overset{textrm{m}}{.}1)，高于SN II的平均水平。在达到最大光度之前的光谱中，观测到了高激发发射线，这是冲击波涌向恒星表面时爆发的星周物质电离的特征。然而，在最大值出现后大约 20 天，光谱与 SN II 的典型光谱并无不同。在这一阶段，包层膨胀的速率大约为3500千米/秒（{}^{-1}/），比SN II的平均值要小一些。
{"title":"SN 2022prv: Bright Type-II Supernova with Signs of Interaction with Circumstellar Matter","authors":"D. Yu. Tsvetkov, V. P. Goransky, E. A. Barsukova, A. F. Valeev, N. N. Pavlyuk, A. V. Dodin, N. I. Shatsky, S. A. Potanin, N. P. Ikonnikova, M. A. Burlak, A. A. Belinsky, V. A. Echeistov, A. S. Vinokurov, A. N. Sarkisyan, A. V. Zharova","doi":"10.1134/s1990341324700275","DOIUrl":"https://doi.org/10.1134/s1990341324700275","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The results of photometric and spectroscopic observations of supernova SN 2022prv carried out with six telescopes including the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences and the 2.5-m telescope of the Caucasus Mountain Observatory of SAI MSU are presented. The dates and magnitudes at the brightness maximum and the parameters of the light curves are determined. The photometric evolution of SN 2022prv is characterized by a constant decrease in brightness after the maximum at a rate quite high for a type II supernovae. Approximately 55 days after the maximum, the rate of the decrease in brightness increased. The maximum luminosity has reached <span>(M_{V}=-18overset{textrm{m}}{.}1)</span> which is higher than average for SN II. In the pre-maximum spectra, high-excitation emission lines were observed characteristic of the ionization of the circumstellar matter by a burst during the shock wave emergence onto the surface of the star. However, approximately 20 days after the maximum, the spectrum did not differ from that typical of SN II. The rate of the envelope expansion at this stage was about 3500 km s<span>({}^{-1})</span> which is a little smaller than average for SN II values.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867854","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}
Pub Date : 2024-07-31DOI: 10.1134/s1990341324600017
K. T. Mirtadjieva, S. N. Nuritdinov, A. U. Omonov
Abstract
In this paper, the phenomenon of lopsidedness associated with the observed effect of displacement of the core of a spiral galaxy from its geometric center is explained by the gravitational instability of individual perturbation modes. The main ones are perturbation modes with radial wave numbers (N=3) and (N=5), where the azimuthal index is (m=1). Unlike other authors, we studied the lopside instability phenomenon against the background of a non-stationary model of a nonlinearly pulsating disk. The mechanisms and criteria for the origin of the phenomenon of displacement of the core in spiral galaxies are revealed. In addition, to determine the dependence of this effect on the geometry of the gravitating system, we also carried out an analysis of lopsided perturbation modes in the framework of a spherical nonstationary model.
{"title":"On the Theory of Formation of Lopsided Spiral Galaxies","authors":"K. T. Mirtadjieva, S. N. Nuritdinov, A. U. Omonov","doi":"10.1134/s1990341324600017","DOIUrl":"https://doi.org/10.1134/s1990341324600017","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>In this paper, the phenomenon of lopsidedness associated with the observed effect of displacement of the core of a spiral galaxy from its geometric center is explained by the gravitational instability of individual perturbation modes. The main ones are perturbation modes with radial wave numbers <span>(N=3)</span> and <span>(N=5)</span>, where the azimuthal index is <span>(m=1)</span>. Unlike other authors, we studied the lopside instability phenomenon against the background of a non-stationary model of a nonlinearly pulsating disk. The mechanisms and criteria for the origin of the phenomenon of displacement of the core in spiral galaxies are revealed. In addition, to determine the dependence of this effect on the geometry of the gravitating system, we also carried out an analysis of lopsided perturbation modes in the framework of a spherical nonstationary model.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867855","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}
Pub Date : 2024-05-08DOI: 10.1134/s1990341324600054
F. G. Kopylova, A. I. Kopylov
Abstract
This work is a continuation of the work of Kopylova and Kopylov published in 2016 on constructing the fundamental plane (FP) of groups and clusters of galaxies. In this article, the sample of galaxy systems has been increased from 94 to 172 objects. We have studied the relationships between the main characteristics of groups and clusters of galaxies using archival data from the SDSS, 2MASX, and NED catalogs. The measured parameters ((log L_{K}), (log R_{e}) and (logsigma)) of galaxy clusters define the fundamental plane in the near-infrared region: (L_{K}propto R_{e}^{0.77pm 0.09}sigma^{1.44pm 0.12}). The shape of the FP of groups and clusters is consistent with the FP of early-type galaxies (SDSS, (r)-filter), determined in the same way. Regression against (log R_{e}) in kpc gives the projection of the FP: (log R_{e}=0.98(pm 0.06),logsigma-0.56(pm 0.04)langlelog I_{e}rangle+3.57(pm 0.07)), which can be used to determine the distances of galaxy systems. The (rms) scatter of the zero point is 0.07, which is equivalent to a 16(%) error in determining the distance to a group or cluster of galaxies. For the first time, we have determined the average relative FP distances and peculiar velocities of five large superclusters of galaxies. According to our estimates, the average peculiar velocity of these superclusters relative to the CMB is (+75pm 360) km s({}^{-1}).
{"title":"Fundamental Plane of Groups and Clusters of Galaxies: Distances and Pecular Velocities of Superclusters of Galaxies on Small Scales","authors":"F. G. Kopylova, A. I. Kopylov","doi":"10.1134/s1990341324600054","DOIUrl":"https://doi.org/10.1134/s1990341324600054","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This work is a continuation of the work of Kopylova and Kopylov published in 2016 on constructing the fundamental plane (FP) of groups and clusters of galaxies. In this article, the sample of galaxy systems has been increased from 94 to 172 objects. We have studied the relationships between the main characteristics of groups and clusters of galaxies using archival data from the SDSS, 2MASX, and NED catalogs. The measured parameters (<span>(log L_{K})</span>, <span>(log R_{e})</span> and <span>(logsigma)</span>) of galaxy clusters define the fundamental plane in the near-infrared region: <span>(L_{K}propto R_{e}^{0.77pm 0.09}sigma^{1.44pm 0.12})</span>. The shape of the FP of groups and clusters is consistent with the FP of early-type galaxies (SDSS, <span>(r)</span>-filter), determined in the same way. Regression against <span>(log R_{e})</span> in kpc gives the projection of the FP: <span>(log R_{e}=0.98(pm 0.06),logsigma-0.56(pm 0.04)langlelog I_{e}rangle+3.57(pm 0.07))</span>, which can be used to determine the distances of galaxy systems. The <span>(rms)</span> scatter of the zero point is 0.07, which is equivalent to a 16<span>(%)</span> error in determining the distance to a group or cluster of galaxies. For the first time, we have determined the average relative FP distances and peculiar velocities of five large superclusters of galaxies. According to our estimates, the average peculiar velocity of these superclusters relative to the CMB is <span>(+75pm 360)</span> km s<span>({}^{-1})</span>.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140934899","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}
Pub Date : 2024-05-08DOI: 10.1134/s1990341323600400
O. Ya. Yakovlev, A. F. Valeev, G. G. Valyavin, V. N. Aitov, G. Sh. Mitiani, T. A. Fathullin, G. M. Beskin, A. V. Tavrov, O. I. Korablev, G. A. Galazutdinov, V. V. Vlasyuk, E. V. Emelianov, V. V. Sasyuk, A. V. Perkov, S. F. Bondar, T. E. Burlakova, S. N. Fabrika, I. I. Romanyuk
Abstract
The light curves for almost 50 thousand stars with magnitudes (min[11overset{textrm{m}}{.}5,19overset{textrm{m}}{.}5]) have been obtained over 2.5 years at SAO RAS in the process of conducting an exoplanet survey in roughly (1overset{circ}{.}5)-sized fields around the white dwarfs WD 0009(+)501 and GRW (+)708247. In this paper we present a catalog of variable stars that have been found in the considered regions. Periodogram analysis was used as the main variation search method. The catalog includes 150 periodic variable stars: 113 of them have been known previously, and for the remaining 37 variations have been discovered for the first time. These stars were classified according to the nature of the variations into four eclipsing variable and three pulsating types, as well as rotating stars. We present the periods and variation amplitudes in the range of (Pin[0overset{textrm{d}}{.}036,32overset{textrm{d}}{.}14]) and (Delta min[0overset{textrm{m}}{.}0064,1overset{textrm{m}}{.}45]), determined from the investigated data.
Abstract The light curves for almost 50 thousand stars with magnitudes （m/in[11verset{textrm{m}}{.}5,19verset{textrm{m}}{.}5]） have been obtained over 2.在白矮星 WD 0009(+)501 和 GRW(+)708247 周围的大约 (1verset{circ}{.}5)大小的场中进行系外行星巡天的过程中，在 SAO RAS 进行了为期 5 年的观测。在本文中，我们介绍了在所考虑的区域内发现的变星星表。周期图分析被用作主要的变星搜索方法。星表中包括150颗周期变星：其中113颗是以前已知的，其余37颗变星是首次发现的。根据变异的性质，这些恒星被分为四种蚀变型和三种脉动型，以及旋转型恒星。我们给出了根据调查数据确定的周期和变幅范围（Pin[0verset{textrm{d}}{.}036,32verset{textrm{d}}{.}14]）以及（Delta min[0verset{textrm{m}}{.}0064,1overset{textrm{m}}{.}45] ）。
{"title":"Catalog of Variable Stars in the WD 0009 $$boldsymbol{+}$$ 501 and GRW $$boldsymbol{+}$$ 708247 Fields Based on Photometric Survey Data on Transiting Exoplanets","authors":"O. Ya. Yakovlev, A. F. Valeev, G. G. Valyavin, V. N. Aitov, G. Sh. Mitiani, T. A. Fathullin, G. M. Beskin, A. V. Tavrov, O. I. Korablev, G. A. Galazutdinov, V. V. Vlasyuk, E. V. Emelianov, V. V. Sasyuk, A. V. Perkov, S. F. Bondar, T. E. Burlakova, S. N. Fabrika, I. I. Romanyuk","doi":"10.1134/s1990341323600400","DOIUrl":"https://doi.org/10.1134/s1990341323600400","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The light curves for almost 50 thousand stars with magnitudes <span>(min[11overset{textrm{m}}{.}5,19overset{textrm{m}}{.}5])</span> have been obtained over 2.5 years at SAO RAS in the process of conducting an exoplanet survey in roughly <span>(1overset{circ}{.}5)</span>-sized fields around the white dwarfs WD 0009<span>(+)</span>501 and GRW <span>(+)</span>708247. In this paper we present a catalog of variable stars that have been found in the considered regions. Periodogram analysis was used as the main variation search method. The catalog includes 150 periodic variable stars: 113 of them have been known previously, and for the remaining 37 variations have been discovered for the first time. These stars were classified according to the nature of the variations into four eclipsing variable and three pulsating types, as well as rotating stars. We present the periods and variation amplitudes in the range of <span>(Pin[0overset{textrm{d}}{.}036,32overset{textrm{d}}{.}14])</span> and <span>(Delta min[0overset{textrm{m}}{.}0064,1overset{textrm{m}}{.}45])</span>, determined from the investigated data.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140932422","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}
Pub Date : 2024-05-08DOI: 10.1134/s1990341323600254
N. G. Beskrovnaya, N. R. Ikhsanov
Abstract
The problem caused by the inconsistency between the age and spin-down time scale of the white dwarfs in the systems AR Sco and AE Aqr is discussed within the hypothesis of their accretion-driven spin-up during the previous epoch. Considering a scenario of accretion from a Keplerian disk, we conclude that the white dwarfs in these systems could be spun-up to the currently observed periods provided the radius of their magnetospheres at the spin-up phase was substantially smaller than the Alfven radius. We show that the required magnetospheric radius value can be reached if the accretion flow penetrates the magnetic field of the white dwarf at its magnetospheric boundary due to anomalous (Bohm) diffusion. In this case the spin-up of the white dwarfs in the systems under consideration can be described based on a model of stationary accretion from the Keplerian disk at an average rate of (10^{-9}{-}10^{-8}M_{odot}) yr({}^{-1}) without any additional assumptions about the evolution of the intrinsic magnetic field of the white dwarfs during the spin-up phase.
摘要 我们讨论了 AR Sco 和 AE Aqr 系统中的白矮星的年龄和自旋下降时间尺度不一致所引起的问题，并提出了它们在上一纪元由吸积驱动自旋上升的假说。考虑到从开普勒盘吸积的情况，我们得出结论，如果这些星系中的白矮星在自旋上升阶段的磁层半径大大小于阿尔弗文半径，那么它们可以自旋上升到目前观测到的周期。我们的研究表明，如果吸积流由于反常（玻姆）扩散而穿透了白矮星磁层边界的磁场，就可以达到所需的磁层半径值。在这种情况下，我们所考虑的系统中白矮星的自旋上升可以根据开普勒磁盘的静态增殖模型来描述，其平均速率为(10^{-9}{-}10^{-8}M_{odot}) yr({}^{-1}) ，而不需要对自旋上升阶段白矮星固有磁场的演化做任何额外的假设。
{"title":"Accretion-driven Spin-up of the White Dwarfs in AR Scorpii and AE Aquarii","authors":"N. G. Beskrovnaya, N. R. Ikhsanov","doi":"10.1134/s1990341323600254","DOIUrl":"https://doi.org/10.1134/s1990341323600254","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The problem caused by the inconsistency between the age and spin-down time scale of the white dwarfs in the systems AR Sco and AE Aqr is discussed within the hypothesis of their accretion-driven spin-up during the previous epoch. Considering a scenario of accretion from a Keplerian disk, we conclude that the white dwarfs in these systems could be spun-up to the currently observed periods provided the radius of their magnetospheres at the spin-up phase was substantially smaller than the Alfven radius. We show that the required magnetospheric radius value can be reached if the accretion flow penetrates the magnetic field of the white dwarf at its magnetospheric boundary due to anomalous (Bohm) diffusion. In this case the spin-up of the white dwarfs in the systems under consideration can be described based on a model of stationary accretion from the Keplerian disk at an average rate of <span>(10^{-9}{-}10^{-8}M_{odot})</span> yr<span>({}^{-1})</span> without any additional assumptions about the evolution of the intrinsic magnetic field of the white dwarfs during the spin-up phase.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140932419","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}
Pub Date : 2024-05-08DOI: 10.1134/s1990341323600278
D. Kh. Bekov, T. A. Akhunov, O. A. Burkhonov, N. R. Alimova
Abstract
The article presents the results of long-term photometric monitoring of two binary gravitationally lensed quasars, SDSS J2124(+)1632 and SDSS J0806(+)2006, carried out at the Maidanak Observatory in 2017–2022. The obtained light curves of the lensed components of both systems are analyzed. The variability of SDSS J2124(+)1632 turned out to be quite large: up to (0overset{textrm{m}}{.}50) for the system as a whole and up to (0overset{textrm{m}}{.}75) for component A. Long-term microlensing was found against the background of a general increase in the apparent brightness of the quasar source. The brightness variations in SDSS J0806(+)2006 are less intense: the range is about (0overset{textrm{m}}{.}20) for the system as a whole, and up to (0overset{textrm{m}}{.}25) for both components. Analysis of the light curves did not show the presence of microlensing here. We also calculated the probable values of the time delay: (Delta t_{textrm{AB}}=102pm 20) days (component B is in the lead) and (Delta t_{textrm{AB}}=-53.0pm 6.0) days (component A is in the lead) in SDSS J2124(+)1632 and SDSS J0806(+)2006, respectively. The value of (Delta t_{textrm{AB}}) for SDSS J2124(+)1632 is consistent with previously found time delays for binary gravitationally lensed systems. In the case of the second system, the time delay is consistent with earlier theoretical calculations, which suggested that the time delay should be about 50 days.
{"title":"Light Curves of Lensed Components and Time Delay Measurements in the Binary Gravtationally Lensed Quasars SDSS J2124 $$+$$ 1632 and SDSS J0806 $$+$$ 2006","authors":"D. Kh. Bekov, T. A. Akhunov, O. A. Burkhonov, N. R. Alimova","doi":"10.1134/s1990341323600278","DOIUrl":"https://doi.org/10.1134/s1990341323600278","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The article presents the results of long-term photometric monitoring of two binary gravitationally lensed quasars, SDSS J2124<span>(+)</span>1632 and SDSS J0806<span>(+)</span>2006, carried out at the Maidanak Observatory in 2017–2022. The obtained light curves of the lensed components of both systems are analyzed. The variability of SDSS J2124<span>(+)</span>1632 turned out to be quite large: up to <span>(0overset{textrm{m}}{.}50)</span> for the system as a whole and up to <span>(0overset{textrm{m}}{.}75)</span> for component A. Long-term microlensing was found against the background of a general increase in the apparent brightness of the quasar source. The brightness variations in SDSS J0806<span>(+)</span>2006 are less intense: the range is about <span>(0overset{textrm{m}}{.}20)</span> for the system as a whole, and up to <span>(0overset{textrm{m}}{.}25)</span> for both components. Analysis of the light curves did not show the presence of microlensing here. We also calculated the probable values of the time delay: <span>(Delta t_{textrm{AB}}=102pm 20)</span> days (component B is in the lead) and <span>(Delta t_{textrm{AB}}=-53.0pm 6.0)</span> days (component A is in the lead) in SDSS J2124<span>(+)</span>1632 and SDSS J0806<span>(+)</span>2006, respectively. The value of <span>(Delta t_{textrm{AB}})</span> for SDSS J2124<span>(+)</span>1632 is consistent with previously found time delays for binary gravitationally lensed systems. In the case of the second system, the time delay is consistent with earlier theoretical calculations, which suggested that the time delay should be about 50 days.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140934883","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}
Pub Date : 2024-05-08DOI: 10.1134/s1990341324700251
L. N. Berdnikov, A. K. Dambis
Abstract
All available photometry for the Cepheid KN Cen is analyzed to construct its ((O-C)) diagram spanning a 134-year long time interval. This made it possible for the first time to compute the rate of evolutionary period increase of the Cepheid, (dP/dt=+2.91(pm{1.68})) s yr({}^{-1}), which is consistent with the results of model computations for the third crossing of the instability strip. The test for stability of pulsations proposed by Lombard and Koen confirmed the reality of the evolutionary period change.
Abstract 对仙王座KN Cen的所有现有光度测量进行了分析，以构建其跨越134年长时间间隔的（(O-C)）图。这使得首次计算出仙王座的演化周期增加率成为可能，（(dP/dt=+2.91(pm{1.68})) s yr({}^{-1}), 这与不稳定带第三次交叉的模型计算结果是一致的。Lombard 和 Koen 提出的脉动稳定性检验证实了演化周期变化的真实性。
{"title":"A Search for Evolutionary Changes in the Period of Classical Cepheid KN Cen","authors":"L. N. Berdnikov, A. K. Dambis","doi":"10.1134/s1990341324700251","DOIUrl":"https://doi.org/10.1134/s1990341324700251","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>All available photometry for the Cepheid KN Cen is analyzed to construct its <span>((O-C))</span> diagram spanning a 134-year long time interval. This made it possible for the first time to compute the rate of evolutionary period increase of the Cepheid, <span>(dP/dt=+2.91(pm{1.68}))</span> s yr<span>({}^{-1})</span>, which is consistent with the results of model computations for the third crossing of the instability strip. The test for stability of pulsations proposed by Lombard and Koen confirmed the reality of the evolutionary period change.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140932459","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}
Pub Date : 2024-05-08DOI: 10.1134/s1990341324600078
S. J. Turaev, S. N. Nuritdinov, A. S. Rastorguev, I. U. Tadjibaev
Abstract
In this paper, we analyze the apparent surface density observations of 81 globular clusters provided by Gaia DR2. The problems of analyzing these observations and their differences from similar data obtained using the HST are discussed. Based on the results of this analysis of the quality of observational data and a number of physical considerations, we separate globular clusters into three classes and then consider the issues of modeling the apparent surface density versus distance. The values of the free parameters of the model are found by the symplectic minimization method. The free parameters including the concentration parameter are for the first time found using the 4-parameter generalized model we propose.
{"title":"Problems of Determining the Degree of Star Concentration Towards the Center of Globular Clusters","authors":"S. J. Turaev, S. N. Nuritdinov, A. S. Rastorguev, I. U. Tadjibaev","doi":"10.1134/s1990341324600078","DOIUrl":"https://doi.org/10.1134/s1990341324600078","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>In this paper, we analyze the apparent surface density observations of 81 globular clusters provided by Gaia DR2. The problems of analyzing these observations and their differences from similar data obtained using the HST are discussed. Based on the results of this analysis of the quality of observational data and a number of physical considerations, we separate globular clusters into three classes and then consider the issues of modeling the apparent surface density versus distance. The values of the free parameters of the model are found by the symplectic minimization method. The free parameters including the concentration parameter are for the first time found using the 4-parameter generalized model we propose.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140932460","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}
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