Astronomy Reports最新文献

{"title":"Effect of Different Factors on the Solar Flare Energy","authors":"V. L. Merzlyakov","doi":"10.1134/S1063772925701276","DOIUrl":"10.1134/S1063772925701276","url":null,"abstract":"<p>The factors affecting the energy of the solar flare are being studied. The model of particle acceleration in the magnetic X-singularity has been studied. It has been found that the flare energy depends mainly on the flow of electrons into the acceleration zone. The change in such a flow is determined by the size of the acceleration zone. It has been calculated that for a chromospheric flare source, the vertical length of the acceleration zone has varied from ∼100 to ≈2 × 10³ km and its diameter varies from ∼1 to ≈100 km.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1286 - 1290"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622072","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":"Light Curve Synthesis for Colliding-Wind Binary Systems","authors":"I. I. Antokhin,&nbsp;E. A. Antokhina","doi":"10.1134/S1063772925701239","DOIUrl":"10.1134/S1063772925701239","url":null,"abstract":"<p>The synthesis method which allows one to compute light curves of binary systems in the Roche model is a powerful and widely used analysis tool. However, in its original form, it is not suitable for the analysis of light curves of binary systems in which one or both components have powerful stellar winds. Previously, we proposed a model of a binary system based on the synthesis method and including one component with a wind. In the current paper, we propose a generalization of the model to the case when both components of the binary system have winds. The surface separating the two winds (the contact surface) is calculated within the framework of a steady state model of stellar wind collision. When calculating the light curve, the absorption of stellar radiation in the winds, as well as in the cooling layers located on both sides of the contact surface, is taken into account. The structure of the cooling layers and their surface density are calculated in the radiative shock limit. The algorithm allows one to take into account the asymmetry of the contact surface caused by the Coriolis force, as well as (using pre-calculated tables) the radiative inhibition of the winds in close binary systems. The results of numerical calculations in various test models are presented, clearly demonstrating the need to take into account the influence of the winds on optical light curves in WR + WR, WR + O, and O + O systems.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1239 - 1251"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622196","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":"Spectroscopic Searches for Evolutionary Orbital Period Changes in WR + OB Binaries: the Case of WR 141","authors":"I. A. Shaposhnikov","doi":"10.1134/S106377292470104X","DOIUrl":"10.1134/S106377292470104X","url":null,"abstract":"<p>The results of new low-resolution spectroscopic observations of the short-period system WR 141 (WN5o + O5V–III, <span>(P approx {{21.7}^{d}})</span>), as well as the results of their comparison with the material of previous studies in order to search for an evolutionary change in the orbital period, are presented. A secular increase in the orbital period of WR 141 with a rate <span>(dot {P} = 1.6 pm 0.9)</span> s/yr, corresponding to a mass loss rate <span>({{dot {M}}_{{{text{WR}}}}} = (3.1 pm 1.9) times {{10}^{{ - 5}}} ;{{M}_{ odot }})</span>/yr with the masses of the stars in the system <span>({{M}_{{{text{WR}}}}} = 39 pm 10 ;{{M}_{ odot }})</span> and <span>({{M}_{{text{O}}}} = 37 pm 10; {{M}_{ odot }})</span>, is reported. A correlation between the mass loss rate of WR stars and their mass is discussed.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1145 - 1152"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621766","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":"Numerical Study of Polytropes with n = 1 and Differential Rotation","authors":"T. L. Razinkova,&nbsp;A. V. Yudin,&nbsp;S. I. Blinnikov","doi":"10.1134/S1063772925701367","DOIUrl":"10.1134/S1063772925701367","url":null,"abstract":"<p>The solution space of differentially rotating polytropes with <span>(n = 1)</span> has been studied numerically. The existence of three different types of configurations: from spheroids to thick tori, hockey puck-like bodies and spheroids surrounded by a torus, separate from or merging with the central body has been proved. It has been shown that the last two types appear only at moderate degrees of rotation differentiality, <span>(sigma simeq 2)</span>. Rigid-body or weakly differential rotation, as well as strongly differential, have not led to any “exotic” types of configurations. Many calculated configurations have had extremely large values of parameter <span>(tau )</span>, which has raised the question of their stability with respect to fragmentation.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1423 - 1436"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621769","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":"Search for Weak Components in Pulsar Radiation","authors":"T. V. Smirnova,&nbsp;M. O. Toropov,&nbsp;S. A. Tyul’bashev","doi":"10.1134/S1063772924701014","DOIUrl":"10.1134/S1063772924701014","url":null,"abstract":"<p>The search for weak components outside the main pulse (MP) in the radiation of pulsars at a frequency of 110 MHz observed on the LPA LPI telescope in the Pushchino Multibeam Pulsar Search (PUMPS) has been carried out. The sample included 96 pulsars, for which the signal-to-noise ratio (<span>(S{text{/}}N)</span>) in the main pulse of the average profile during accumulation over 10 years was more than 40. It has been found that PSR J1543+0929 has radiation for almost the entire period. The profile is three-component. The relative amplitudes of the lateral weak components are 0.013 and 0.025. For PSR J2234+2114, a precursor that is <span>(53^circ )</span> away from the MP has been detected.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1185 - 1190"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622139","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":"Properties of Contracting Massive Protostellar Cores","authors":"L. E. Pirogov,&nbsp;P. M. Zemlyanukha,&nbsp;E. M. Dombek","doi":"10.1134/S1063772925701343","DOIUrl":"10.1134/S1063772925701343","url":null,"abstract":"<p>Studies of the structure and kinematics of cores associated with the regions of massive star and star cluster formation are necessary for constructing scenario for the evolution of these objects. We analyzed spectral maps of the massive cores of G012.418+00.506, G326.472+00.888, G328.567–00.535, G335.586–00.289 and G343.127–00.063 from the MALT90 survey in the HCO⁺(1–0) and H¹³CO⁺(1–0) lines. The cores are at different stages of evolution and have signs of contraction. By fitting spectral maps calculated within the framework of a spherically symmetric model into the observed ones, the parameters of the radial profiles of density, turbulent velocity and contraction velocity were calculated. The power-law index of the density decay with distance from the center varies in the range of <span>( sim {kern 1pt} 1.5{kern 1pt} - {kern 1pt} 2.8)</span>. The lowest value is obtained for the core of G326.472+00.888 without internal sources. The contraction velocity in all cores depends weakly on the distance to the center, decreasing with an index of ~0.1, which differs from the free-fall mode. There are indications of rotation for the cores of G328.567–00.535 and G335.586–00.289. Analysis of ¹³CO(2–1) data from the SEDIGISM survey for the regions G012.418+00.506, G335.586–00.289, and G343.127–00.063 revealed motions from the surrounding gas toward the cores. The results obtained indicate that the massive cores under consideration interact with their environment and are apparently in a state of global co-llapse.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1390 - 1405"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621826","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":"Detection and Study of a Number of Transients on Telescopes of the MASTER Global Network and MASTER OT J044907.58+705812.7 as an Example","authors":"V. M. Lipunov,&nbsp;P. V. Balanutsa,&nbsp;E. P. Pavlenko,&nbsp;A. A. Sosnovskij,&nbsp;A. N. Tarasenkov,&nbsp;I. E. Panchenko,&nbsp;K. A. Antonyuk,&nbsp;O. I. Antonyuk,&nbsp;O. A. Gress,&nbsp;A. S. Kuznetsov,&nbsp;K. K. Zhirkov,&nbsp;N. V. Tyurina,&nbsp;A. R. Chasovnikov,&nbsp;G. A. Antipov,&nbsp;E. S. Gorbovskoy,&nbsp;A. N. Yudin,&nbsp;V. V. Topolev,&nbsp;D. V. Cheryasov,&nbsp;D. M. Vlasenko,&nbsp;Y. Kechin,&nbsp;V. A. Senik,&nbsp;A. F. Iyudin,&nbsp;N. M. Budnev,&nbsp;A. G. Tlatov,&nbsp;K. A. Vetrov,&nbsp;M. A. Gulyaev,&nbsp;V. V. Chazov,&nbsp;V. V. Vladimirov,&nbsp;D. S. Zimnukhov","doi":"10.1134/S1063772925701318","DOIUrl":"10.1134/S1063772925701318","url":null,"abstract":"<p>In this paper, details of the detection of new object MASTER OT J044907.58+705812.7 (AT2024aaf) discovered on January 14, 2024 during a regular survey using the MASTER-Tunka telescope of the MASTER Global Network of Moscow State University have been present. Additional photometry of the object during joint observations at AZT-11 and 2.6-m ZTSh telescopes of CrAO RAS, MASTER-Tunka, and MASTER-Kislovodsk telescopes has been obtained. Large amplitude <span>(( &gt; {kern 1pt} {{7}^{m}}))</span>, blue color at maximum, brightness fluctuations during the flare with a characteristic time of ~0.06 days, long (at least 50 days) return to a calm state, the presence of at least four repeated rebrightenings gives grounds to classify the object as a dwarf nova of the WZ Sge type with multiple rebrightenings. In the paper, details of the detection of flares of other dwarf novae: MASTER OT J195416.74+494421.1, MASTER OT J150719.46–283114.9, MASTER OT J185835.32–354042.2, MASTER OT J174714.38+150048.1, and MASTER OT J065054.42+593625.5 as an example of the operation of software for processing wide-field images and identifying new and variable sources in them in real time have also been provided.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1364 - 1375"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621832","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":"Study of the Interplanetary Coronal Mass Ejection (ICME) Disturbances of Different Structure Types between 1995 and 2022 and Their Relative Geoeffectiveness: Superposed Epoch Analysis","authors":"W. Alotaibi,&nbsp;B. Badruddin","doi":"10.1134/S1063772924600353","DOIUrl":"10.1134/S1063772924600353","url":null,"abstract":"<p>This study presents an analysis of the solar wind plasma and field parameters and geomagnetic indices response to 255 events between 1995 and 2022 with Disturbance storm time <i>Dst</i> ≤ –30 nT. The events were divided into nine groups and structures. Superposed epoch analysis was performed on the selected events to study the effect based on each group. We also performed a correlation analysis between geomagnetic indices, solar wind plasma and field parameters. We found that <i>Dst</i> has a strong correlation with Planetary Kp index (<i>Ap</i>) and a moderate correlation with Auroral Electrojet index (<i>AE</i>), while ap has a strong correlation with <i>Dst</i> and <i>AE</i>. Duskward electric field (<i>Ey</i>) is consistently better related to all three geomagnetic indices (<i>Dst</i>, <i>Ap</i> and <i>AE</i>), <i>Dst</i> relation is relatively stronger with <i>Bz</i> than <i>Ey</i>. Other two indices (<i>Ap</i> and <i>AE</i>) correlation is relatively weaker with <i>Bz</i> than <i>Ey</i>. In addition to <i>Ey</i>, another interplanetary parameter, the interplanetary electric field (<i>BV</i>), correlates reasonably well with the <i>Ap</i> and <i>AE</i> indices. Thus, <i>Ey</i> can be universally used as coupling function in all three domains (equatorial, mid-latitude and polar), represented by <i>Dst</i>, <i>Ap</i>, and <i>AE</i> indices, respectively. However, <i>Bz</i> in the equatorial, and <i>BV</i> in the mid-latitude and equatorial regions, may also be considered as alternate coupling functions. Best-fit linear equations obtained between geomagnetic indices and best-related field parameters can be utilized to estimate the expected strength of geomagnetic disturbances in the equatorial, mid-latitude and polar regions using plasma/field observations during passage of ICME associated structures. Furthermore, we investigated the recovery phase of each parameter within each group. We observed a strong correlation between the time constants of the geomagnetic indices, both amongst themselves and with <i>Bz</i>.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1303 - 1316"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621974","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":"Third Light in the SS 433 System according to UBVRcIc Photometry","authors":"A. V. Dodin,&nbsp;A. M. Cherepashchuk,&nbsp;K. A. Postnov,&nbsp;M. A. Burlak,&nbsp;N. P. Ikonnikova","doi":"10.1134/S1063772925701306","DOIUrl":"10.1134/S1063772925701306","url":null,"abstract":"<p><i>UBVR</i>_c<i>I</i>_c observations of the microquasar SS 433 from 1980 to 2023 revealed a persistent effect unusual for classical eclipsing binaries. In the phases of maximum accretion disk opening, the depths of the primary and secondary eclipsing minima of the orbital light curve decrease synchronously with increasing wavelength. To explain this effect, we use a model of an eclipsing binary system in which a third non-eclipsed light is present. It is shown that the main source of the third light at a mass loss rate from the system of 10⁻⁴ <span>({{M}_{ odot }})</span>/yr are the peripheral semi-transparent regions of the supercritical accretion disk, as well as an extended part of the disk wind. The contribution of the non-eclipsed third light increases from 15% in the <i>B</i> filter to 40% in the <i>I</i>_<i>c</i> filter. The spectrum of the third non-eclipsed light in the range of 4000–8000 Å corrected for interstellar absorption can be described by a power law with an exponent in the wavelength scale close to –1. Significant variations in the brightness of the system outside eclipses are associated mainly not with the classical effect of the ellipsoidality of the components, but with variable absorption of light from the components in the common envelope of the system formed by powerful winds of the supercritical accretion disk and the donor star.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1349 - 1363"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621831","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":"Influence of Departures from LTE on Determinations of the Sulfur Abundances in A–K Type Stars","authors":"S. A. Korotin,&nbsp;K. O. Kiselev","doi":"10.1134/S1063772924700987","DOIUrl":"10.1134/S1063772924700987","url":null,"abstract":"<p>The influence of departures from local thermodynamic equilibrium (LTE) on neutral sulfur lines is considered. A grid of corrections is proposed to take into account the influence of departures from LTE for neutral sulfur lines in the visible and infrared spectral regions, including the <i>H</i>-band. The grid is calculated using the atomic model of sulfur incorporating the most up-to-date collision rates with electrons and hydrogen. The inclusion of levels and transitions of ionized sulfur in the atomic model made it possible to expand the range of effective temperatures of stellar photospheres in the grid up to 10 000 K. The atomic model was tested in determining the sulfur abundance of 13 stars and showed its adequacy in a wide range of fundamental stellar parameters. In the spectra of all test stars, the sulfur lines are fitted with similar abundances of the element, regardless of the degree of influence of the effects of deviation from LTE on a particular spectral line. For lines of several multiplets, the wavelengths and oscillator strengths were refined. A list of S I lines reco-mmended for determining sulfur abundance has been created.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1159 - 1175"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622138","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}