Astronomy Reports最新文献_第3页

Long-Term Optical Spectroscopy of B[e] Star CI Cam in a Quiet State 静态 B[e] 星 CI Cam 的长期光学光谱分析

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-08-29 DOI: 10.1134/S1063772924700501

V. G. Klochkova, A. S. Miroshnichenko, V. E. Panchuk

{"title":"Long-Term Optical Spectroscopy of B[e] Star CI Cam in a Quiet State","authors":"V. G. Klochkova, A. S. Miroshnichenko, V. E. Panchuk","doi":"10.1134/S1063772924700501","DOIUrl":"10.1134/S1063772924700501","url":null,"abstract":"High-resolution optical spectra of the B[e] star CI Cam were obtained on arbitrary dates 2002–2023 using the 6-meter BTA telescope with the echelle spectrograph NES. The variability over time of the powerful emissions of Hα and He I profiles is found. For two-peak emissions with “rectangular” profiles, the intensity ratio of blue-shifted and red-shifted peaks is ({text{V/R}} geqslant 1), except one date. A decrease in the intensity of all double-peaked emissions with “rectangular” profiles was revealed as they moved away in time from the 1998 outburst. The average radial velocity for emissions of this type for all observation dates varies in the range ({{V}_{r}}({text{emis}}{-} d) = ) ( - (50.8 {div} 55.7) pm 0.2) km/s. The half-amplitude of the change (standard deviation) is equal to (Delta {{V}_{r}} = 2.5) km/s. The velocity for single-peaked ion emissions (Si III, Al III, Fe III) differs little from the values of ({{V}_{r}}({text{emis}}{-} d)), but the measurement accuracy for these emissions is worse: the average error for different dates ranges from 0.4 to 1.3 km/s. The systemic velocity is assumed to be ({{V}_{{{text{sys}}}}} = - 55.4 pm 0.6) km/s according to the stable position of the forbidden emission [N II] 5755 Å. The position of single-peak emissions [O III] 4959 and 5007 Å is also stable: ({{V}_{r}}([{text{O}};{text{III}}]) = ) ( - 54.2 pm 0.4) km/s. Emissions [O I] 5577, 6300, 6363 Å, [Ca II] 7291 and 7324 Å are absent from the spectra. Appearance of the emission near 4686 Å is an infrequent event, its intensity rarely exceeds the noise level. Only a wide asymmetric emission with an intensity of about 16% above the continuum was registered in the spectrum for September 3, 2015. Questions arise about the use of this emission to estimate the period of variability of the star and about localization of this feature in the CI Cam system. The photospheric absorptions of N II, S II, and Fe III with a variable position are identified.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219986","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

ET Dra Activity According to Observations in 2018–2023 2018-2023 年观测到的 ET Dra 活动

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-08-29 DOI: 10.1134/S1063772924700549

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

{"title":"ET Dra Activity According to Observations in 2018–2023","authors":"I. S. Savanov, S. A. Naroenkov, M. A. Nalivkin, A. N. Tarasenkov, E. S. Dmitrienko","doi":"10.1134/S1063772924700549","DOIUrl":"10.1134/S1063772924700549","url":null,"abstract":"The results of new photometric observations of the chromospherically active star ET Dra, performed using telescopes of the Zvenigorod INASAN Observatory, the Russian-Cuban Observatory in the territory of the Republic of Cuba (Havana), and the Terskol INASAN Observatory (a total of 8 sets of observations) with the addition of archival observations of the Kamogata Wide-field Survey. Variations in the shape of the light curve caused by the rotational modulation of a star with spots on the surface, as well as studies of the long-term variability of the star’s brightness, were investigated based on the data acquired in 2018–2023. Characteristic changes in the ET Dra light curve were noted including a decrease of the stellar brightness in the (V) filter, its cyclic variations, and subsequent brightness increase. The shape of the phase curve and the duration of the extended minimum of brightness vary. During the HJD 245 9670–245 9715 interval, the amplitude of the star’s brightness variability reached a maximum value of more than 0.4m, as it was in 1990. The surface temperature inhomogeneities maps were calculated and estimates of the spottedness parameter S of the object were performed for each of the 8 sets of observations. Maximum value of parameter S was 32.2‒33.5%. Based on the constructed power spectra, the values of possible cycles of long-term activity of the star were obtained as 570 and 1160d (1.56 and 3.18 years, respectively).","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219990","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 Detection and Investigation of Exoplanets with MASTER Global Network Telescopes 利用 MASTER 全球网络望远镜探测和调查系外行星

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-08-29 DOI: 10.1134/S1063772924700513

V. M. Lipunov, A. N. Tarasenkov, A. S. Kuznetsov, P. V. Balanutsa, G. A. Antipov, Ya. Yu. Kechin, N. V. Tyurina, E. S. Gorbovskoy, D. A. H. Buckley, C. Francile, F. Podesta, A. G. Tlatov, R. Rebolo Lopez, N. M. Budnev, O. A. Gress, V. V. Yurkov

引用次数: 0

Force Free Magnetic Flux Rope with a High Current Density on the Axis 轴上具有高电流密度的无力磁通绳

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-08-29 DOI: 10.1134/S1063772924700550

A. A. Solov’ev

{"title":"Force Free Magnetic Flux Rope with a High Current Density on the Axis","authors":"A. A. Solov’ev","doi":"10.1134/S1063772924700550","DOIUrl":"10.1134/S1063772924700550","url":null,"abstract":"A new model of a force-free magnetic flux rope with a high concentration of electric current on the axis is presented. The general property of axisymmetric force-free magnetic ropes is that with the exit of the top of the magnetic loop-rope into the corona, the external pressure that keeps it from lateral expansion steadily decreases, and with some critical decrease in this pressure, the longitudinal magnetic field of the rope becomes zero on the surface where the electric current changes its sign (it is current inversion surface—CIS). In this case, the force-free parameter (alpha (r)) and the azimuthal electric current jϕ(r) experience a second-order discontinuity on this surface, so that in the vicinity of CIS their values begin to increase without limit. The current (drift) speed of electrons here will inevitably exceed the speed of ion sound. This serves as a trigger for the heating of non-isothermal plasma (so it turns out Te ( gg ) Ti) and the excitation of plasma ion-acoustic instability of the plasma not only near the CIS, but also in the central region of the rope, on its axis, where the current density is especially high. The appearance of anomalous resistance leads to rapid dissipation of the magnetic field and the generation of a super-Dreicer electric field. The Parker effect, associated with the equalization (with some delay) of the torque along the axis of the rope due to the transfer of the azimuthal field to the region of energy release, leads to quasiperiodic pulsations of hard flare radiation and, ultimately, ensures the flare release of the most part of free magnetic energy accumulated in the rope.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219991","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

Modern Stellar Astronomy 2023 现代恒星天文学 2023

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-08-29 DOI: 10.1134/S1063772924700525

O. Yu. Malkov, E. Yu. Kilpio, O. B. Dluzhnevskaya

引用次数: 0

Time Structure of the Average Rotation Measure for Accretion Disk in Shearing Box Approximation 剪切盒近似法中吸积盘平均旋转测量值的时间结构

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-08-29 DOI: 10.1134/S1063772924700495

M. A. Buldakov, A. S. Andrianov

引用次数: 0

The Evolutionary Status of the Galaxy’s X-ray Binary Stars 银河系 X 射线双星的演化状况

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-08-29 DOI: 10.1134/S1063772924700562

A. V. Tutukov, A. V. Fedorova

{"title":"The Evolutionary Status of the Galaxy’s X-ray Binary Stars","authors":"A. V. Tutukov, A. V. Fedorova","doi":"10.1134/S1063772924700562","DOIUrl":"10.1134/S1063772924700562","url":null,"abstract":"The article is devoted to the analysis of the evolutionary status of the X-ray binary stars of the Galaxy. It is shown that the assumption of the conservative evolution of these binary systems leads to an overestimation of the X-ray luminosity of the Galaxy by 3–4 orders. The total observed rate of accretion of matter by relativistic components of X-ray binaries is close to ( {sim} {{10}^{{ - 6}}}{{M}_{ odot }}{text{/}})yr, while the theoretically possible rate reaches ( {sim} {{10}^{{ - 2}}}{{M}_{ odot }}{text{/}})yr. The contradiction between these estimates is eliminated if two factors are taken into account. The first of them is the formation of a common envelope in massive X-ray binary systems after filling the Roche lobe by the donor and the brief phase of a bright X-ray source. The common envelope eliminates the output of X-ray radiation generated during accretion, and also leads to the loss of part of the donor’s matter from the system. The second factor is the presence of intense stellar wind of donors in massive X-ray binary, as well as the occurrence of induced stellar wind in low-mass donors due to exposure to hard radiation from an accreting relativistic star. At the same time, the generally accepted assumption that donors of X-ray binaries fill their Roche lobes may not be fulfilled. A significant part of the donor’s wind matter may be lost from the system. In addition, radiation can enhance the stellar wind of the accretion disk, and part of this wind will also leave the system. There are other factors that reduce the total number of accreted matter: supernova explosions in X-ray binaries, destroying part of these systems, the impossibility of accretion onto rapidly rotating young neutron stars with a strong magnetic field, as well as a rapid drop in the rate of loss of matter by the donor as its mass decreases, characteristic for low-mass X-ray systems.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219983","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

Determination of the Parameters of the Gravitational Field of the Earth by Gradiometric Measurements in the Earth’s Geocentric Coordinate System 在地球地心坐标系中通过梯度测量确定地球引力场参数

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-08-15 DOI: 10.1134/S1063772924700458

A. A. Kluykov

引用次数: 0

Gas-Dynamical Model of Accretion on a Neutron Star with Viscosity and the Influence of Large-Scale Vortices on the Transmission of Angular Momentum 具有粘度的中子星上的吸积气体动力学模型以及大尺度漩涡对角动量传递的影响

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-08-15 DOI: 10.1134/S1063772924700422

A. G. Aksenov, V. M. Chechetkin

引用次数: 0

V957 CEP—A Zero-Age Eclipsing System V957 CEP-A 零年龄食化系统

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2024-08-15 DOI: 10.1134/S1063772924700446

I. M. Volkov, S. A. Naroenkov, A. S. Kravtsova

{"title":"V957 CEP—A Zero-Age Eclipsing System","authors":"I. M. Volkov, S. A. Naroenkov, A. S. Kravtsova","doi":"10.1134/S1063772924700446","DOIUrl":"10.1134/S1063772924700446","url":null,"abstract":"New high-precision photometric measurements of the V957 Cep system ((P{{ = 1.99}^{d}}), (V{{ = 11.17}^{m}}), (e = 0.127), B6 V+B8 V), as well as an integrated approach to determining orbital parameters based both on photometric solutions of the light curves and the study of the course of residual deviations of the minima timings from the linear formula (O - C) made it possible for the first time to accurately measure the apsidal motion rate: ({{dot {omega }}_{{{text{obs}}}}} = 2.91^circ )/year, which coincided with the theoretical value under the condition of the orbital and axial rotation synchronism: ({{dot {omega }}_{{{text{theor}}}}} = 2.92^circ )/year. The physical parameters of the component stars were obtained: ({{T}_{1}} = 14,550 pm 300) K, ({{M}_{1}} = 4.0 pm 0.2{kern 1pt} {{M}_{ odot }}), ({{R}_{1}} = 2.55 pm 0.05{kern 1pt} {{R}_{ odot }}), ({{T}_{2}} = 12,400 pm 250) K, M2 = 3.0 ± (0.15{kern 1pt} {{M}_{ odot }}), ({{R}_{2}} = 1.88 pm 0.05{kern 1pt} {{R}_{ odot }}). This set of parameters corresponds to stars of zero age, recently descended to ZAMS. The secondary component is a pulsating variable star of the (beta ) Cephei type.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219989","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