Astronomy Reports最新文献_第9页

Analysis of the Effect of Earth’s Equatorial Ellipticity on the Existence and Stability of the Lagrangian Points in the Earth–Moon–Sun System 地球赤道椭圆度对地月日系统中拉格朗日点的存在和稳定性的影响分析

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923340036

Mukesh Kumar, Sushil Yadav

引用次数: 0

The Formation and the Evolution of Large-Scale Vortex Structures in Stellar Accetion Disks 恒星加速盘中大规模涡旋结构的形成与演化

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923120053

Z. D. Livenets, A. Yu. Lugovsky

{"title":"The Formation and the Evolution of Large-Scale Vortex Structures in Stellar Accetion Disks","authors":"Z. D. Livenets, A. Yu. Lugovsky","doi":"10.1134/S1063772923120053","DOIUrl":"10.1134/S1063772923120053","url":null,"abstract":"Explaining the causes of angular momentum transfer in accretion stellar disks is an important astrophysical problem, since it is the process that determines the rate of accretion of matter onto the central gravitating body. Previously, within the framework of a two-dimensional approach, it was shown that the introduction of small perturbations into the flow of accretion disk leads to the appearance of shear instability. This process is accompanied by the development of large-scale vortex structures. Their movement and evolution lead to a redistribution of angular momentum in the accretion disk. The action of the described mechanism was previously studied numerically only within a two-dimensional approximation, so the goal of the current work is to carry out full-scale three-dimensional modeling. The processes under study are described within the framework of the system of equations of ideal gas dynamics. The article briefly describes the method for their numerical integration, which is based on a conservative finite-difference scheme and the solution of the Riemann problem. The initial data is a stationary toroidal gas state surrounded by a matter with low density and pressure. At the next step, small perturbations of one of the gas-dynamic variables are introduced. The modeling and analysis of the results of numerical calculations show the emergence of vortex structures in the shear flow of a three-dimensional accretion disk. Their movement is accompanied by a redistribution of matter and angular momentum in the volume of the disk, leading to accretion of matter onto the central body.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139978668","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}

引用次数: 0

The Origin of the Solar Activity 太阳活动的起源

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923130103

S. A. Yazev, L. L. Kitchatinov

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Electromagnetic Field of a Charged Particle, Asymptotically Approaching Schwarzschild Black Hole 渐近施瓦兹柴尔德黑洞的带电粒子电磁场

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923140111

S. O. Komarov, A. K. Gorbatsievich, G. V. Vereshchagin, A. S. Garkun

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On the Influence of Pauli Blocking on Pair Creation in Strong Electric Field 论强电场中保利封阻对成对的影响

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923140159

M. A. Prakapenia, G. V. Vereshchagin

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Sunspots, Solar Flares, and Coronal Partings 太阳黑子、太阳耀斑和日冕碎裂

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923130097

S. A. Yazev

引用次数: 0

Polarized Light from Accreting Low Mass X-Ray Binaries 来自吸积低质量 X 射线双星的偏振光

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923140044

F. Capitanio, A. Gnarini, S. Fabiani, F. Ursini, R. Farinelli, M. Cocchi, N. Rodriguez Cavero, L. Marra

引用次数: 0

Luminosity Outbursts in Interacting Protoplanetary Systems 相互作用原行星系统中的光度爆发

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923120107

A. M. Skliarevskii, E. I. Vorobyov

{"title":"Luminosity Outbursts in Interacting Protoplanetary Systems","authors":"A. M. Skliarevskii, E. I. Vorobyov","doi":"10.1134/S1063772923120107","DOIUrl":"10.1134/S1063772923120107","url":null,"abstract":"FU Orionis type objects (fuors) are characterized by rapid (tens to hundreds years) episodic outbursts, during which the luminosity increases by orders of magnitude. One of the possible causes of such events is a close encounter between stars and protoplanetary disks. Numerical simulations show that the fuor-like outburst ignition requires a very close encounter ranging from a few to a few tens of astronomical units. In contrast, the observed stellar objects in fuor binaries are usually hundreds of astronomical units apart. Simple mathematical estimates show that if such a close approach took place, the binary stellar components would have an unrealistic relative velocity, at least an order of magnitude greater than the observed velocity dispersion in young stellar clusters. Thus, the bursts are either triggered with a certain delay after passage of the periastron or their ignition does not necessary require a close encounter and hence the outburst is not caused by the primordial gravitational perturbation of the protoplanetary disk. In this work, an encounter of a star surrounded by a protoplanetary disk with a diskless external stellar object was modeled using numerical hydrodynamics simulations. We showed that even fly-bys with a relatively large periastron (at least 500 AU) can result in fuor-like outbursts. Moreover, the delay between the periastron passage and the burst ignition can reach several kyr. It was shown for the first time by means of numerical modeling that the perturbation of the disk caused by the external object can trigger a cascade process, which includes the development of the thermal instability in the innermost disk followed by the magneto-rotational instability ignition. Because of the sequential development of these instabilities, the rapid increase in the accretion rate occurs, resulting in the luminosity increase by more than two orders of magnitude.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140884828","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}

引用次数: 0

The Transformation of the Rotational Energy of an Accreting Kerr Black Hole 增殖克尔黑洞旋转能量的转变

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923140202

Shu-Rui Zhang

引用次数: 0

Activity Cycles of the Star FK Com FK Com 星的活动周期

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-02-25 DOI: 10.1134/S1063772923120089

I. S. Savanov, S. A. Naroenkov, M. A. Nalivkin, E. S. Dmitrienko

{"title":"Activity Cycles of the Star FK Com","authors":"I. S. Savanov, S. A. Naroenkov, M. A. Nalivkin, E. S. Dmitrienko","doi":"10.1134/S1063772923120089","DOIUrl":"10.1134/S1063772923120089","url":null,"abstract":"We present the results of our photometric observations of the chromospherically active star FK Com (prototype of its group of stars) acquired during the recent 5 years (2018–2023) at the INASAN observatories in Zvenigorod and Simeiz and at the Russian–Cuban observatory in Habana (Republic of Cuba). In total, we obtained 9060 estimates of the star’s brightness in the V filter between 2018 and 2023. Our measurements, as well as data from the literature and from the Kamogata Wide-field Survey (KWS) archive, were combined into a unified set containing 17 653 measurements for a time interval about 57 years long. Based on the power spectrum derived from these data, we identified possible activity cycles ({{P}_{{{text{cycl}}}}}), estimated by us to be 2.4, 5.63, 8, 13.6, 30, and 49 years. The dominating ({{P}_{{{text{cycl}}}}}) is 5.63 years long. We show that the dominating cycle found by us from extensive data to be about 5.63 years (5.4–5.8 years from other sources in the literature) can also be noticed from the analysis of earlier studies. We compared our results on the activity cycles of FK Com to data on long-term variations of two other stars of the same type, HD 199178 (V1794 Cyg) and ET Dra. Data on ({{P}_{{{text{cycl}}}}}) of other chromospherically active stars (from the literature and from our measurements) were used to analyze the (log (1{text{/}}{{P}_{{{text{rot}}}}}){-} log ({{P}_{{{text{cycl}}}}}{text{/}}{{P}_{{{text{rot}}}}})) diagram. We make a conclusion on the compatibility of our determinations of activity cycles for stars of the FK Com type with data for RS CVn stars.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140884832","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}

引用次数: 0