Astronomy Reports最新文献

{"title":"Modeling of Hot Jupiter HAT-P-32b and Transit Absorptions in Excited Hydrogen and Helium Atom Lines","authors":"S. S. Sharipov,&nbsp;I. F. Shaikhislamov,&nbsp;I. B. Miroshnichenko,&nbsp;M. S. Rumenskikh,&nbsp;A. V. Shepelin,&nbsp;M. P. Golubovsky","doi":"10.1134/S106377292570204X","DOIUrl":"10.1134/S106377292570204X","url":null,"abstract":"<p>The results of absorption modeling in the hydrogen Hα 6563 Å and helium 10830 Å lines for hot Jupiter HAT‑P-32b have been presented. The modeling has been performed using a three-dimensional hydrodynamic code together with the Monte Carlo model of Lyα photon transport. A wide range of stellar radiation and atmospheric parameters has been considered. It has been found that the measured spectrally resolved transit absorption in both lines can be well described by model calculations with the stellar radiation in the XUV range limited to 200 erg/cm²/s per 1 AU, the helium content in the planet’s atmosphere is He/H = 2/98, and metallicity is [Fe/H] = –1. It has been shown that absorption in the helium line occurs uniformly in a large volume of the outflowing atmosphere, and in the hydrogen line, it occurs in a layer of 1.5–2.75 planet radii.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"69 8","pages":"708 - 721"},"PeriodicalIF":0.7,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184173","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":"Dynamical Orbital Stability Analyses of Eclipsing Binaries with Additional Companions","authors":"M. E. Kenger,&nbsp;H. Er,&nbsp;A. Özdönmez","doi":"10.1134/S1063772924600444","DOIUrl":"10.1134/S1063772924600444","url":null,"abstract":"<p>In the study, the dynamical stability of 41 eclipsing binary (EB) systems proposed to host one or two additional bodies was examined, as reported in the literature. Using the REBOUND N-body integration package, we employed the WHFast and IAS15 integrators alongside the MEGNO (Mean Exponential Growth Factor of Nearby Orbits) indicator to conduct detailed orbital stability simulations over a period of 10 Myr. For systems exhibiting signs of instability on shorter timescales, MEGNO analyses were performed to identify chaotic behavior more effectively. Of the 41 systems analyzed, all 31 systems with a single proposed additional body demonstrated stable (non-chaotic) orbital configurations. Conversely, among the 10 systems proposed to host two additional bodies, only FK Aql exhibited stability, while the remaining systems displayed chaotic behavior, highlighting the challenges of maintaining long-term stability in multi-companion configurations. MEGNO analyses for FK Aql over 10⁸ years confirmed its placement in a dynamically stable region, with MEGNO chaos parameter values (<span>(langle Yrangle leqslant 2)</span>), consistent with its orbital stability timeline. In contrast, MEGNO maps for the remaining multi-companion systems corroborated their chaotic timelines, confirming their instability. The combination of orbital stability timelines and MEGNO maps provides complementary insights into the long-term dynamics of these systems. This approach underscores the necessity of incorporating stability analyses into studies of binary systems to refine our understanding of their complex gravitational interactions.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"69 8","pages":"758 - 765"},"PeriodicalIF":0.7,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184152","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":"On Detection of Co-Rotating Regions of Interaction of Solar Wind Flows Based on Monitoring Data of Interplanetary Scintillation","authors":"V. R. Lukmanov,&nbsp;I. V. Chashei,&nbsp;S. A. Tyul’bashev,&nbsp;I. A. Subaev","doi":"10.1134/S1063772925702051","DOIUrl":"10.1134/S1063772925702051","url":null,"abstract":"<p>A model for co-rotating interaction regions of multispeed solar wind flows including a region with a reduced level of small-scale turbulence in front of the compressed part has been proposed. This model is a development of the previously proposed model for the leading part of the interaction region. Dynamic two-dimensional maps of the distribution of the interplanetary scintillation level adapted to observations using the LPA LPI radio telescope have been calculated based on the model. As an example, an event related to a magnetic storm on April 16–17, 2024 has been considered. A comparison of model calculations with observational data, which confirmed the previously made assumption that the scintillation attenuation at night before the arrival of a disturbance to the Earth is associated with an area of reduced small-scale turbulence, has been carried out. In general, the qualitative model calculations are in good agreement with the observational data.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"69 8","pages":"722 - 728"},"PeriodicalIF":0.7,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1134/S1063772925702051.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stellar Wind of Components of Detached Binary Systems","authors":"A. V. Tutukov,&nbsp;A. V. Sobolev","doi":"10.1134/S1063772925702038","DOIUrl":"10.1134/S1063772925702038","url":null,"abstract":"<p>The paper is devoted to the consideration of the role of the donor stellar wind in the matter exchange between the components of detached binary systems. A classification of close binary systems with interacting components is proposed. A list of potential donors and accretors of such systems, including X-ray binary and symbiotic stars, is given. Analytical tasks have been completed to evaluate the conditions and efficiency of interaction through the stellar wind, a criterion was found for maintaining the self-induced stellar wind of X-ray binaries, and a condition for the formation of an accretion disk during accretion of stellar wind matter by a compact accretor. Three-dimensional gas dynamic models of component interaction are constructed for the five initial velocities of the stellar wind using the example of Sco X-1 type systems. The simulation results are illustrated by pictures of streamlines, temperature distribution, and wind gas densities in the orbital and frontal planes. Model focusing of the donor wind flow by the accretor is confirmed by the observed phase X-ray light curve of Vela X-1.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"69 8","pages":"652 - 684"},"PeriodicalIF":0.7,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184131","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":"A Two-Planet Problem with an Arbitrary Inclination of a Pair of Orbits. Secular Evolution of the Kepler-117 Exosystem","authors":"B. P. Kondratyev,&nbsp;V. S. Kornoukhov","doi":"10.1134/S1063772925702026","DOIUrl":"10.1134/S1063772925702026","url":null,"abstract":"<p>A new method is used to study a current version of the two-planet problem on the secular evolution of planetary orbits with small eccentricities and mutual inclinations, having an arbitrary orientation relative to the main (picture) plane. A model has been developed that describes a wide class of exoplanetary systems with an inclination angle of orbits different from <span>(pi {text{/}}2.)</span> The orbits of the planets are modeled by the Gaussian rings, the perturbing function is represented by the mutual gravitational energy of these rings in the form of a series up to terms of second order of smallness. To describe the evolution of orbits, instead of osculating Keplerian elements, a new set of variables is introduced: the unit vector <span>({mathbf{R}})</span> of normal to the plane of the ring and two Poincaré variables <span>(left( {p,q} right);)</span> for eight independent variables, a system of differential equations is obtained and analytically solved. The method is applied to study the secular evolution of the two-planet system Kepler-117 (KOI-209) with non-resonant orbits of exoplanets. It has been established that in this system the oscillations of the same components of the orientation vector <span>({mathbf{R}})</span> for each of the orbits, as well as the values <span>(left( {e,i,{{Omega }}} right),)</span> occur strictly in antiphase. The eccentricities of both orbits oscillate with the period <span>({{T}_{kappa }} approx 182.3;{text{years}},)</span> and the inclinations of the orbits and the longitudes of the ascending nodes change in the libration mode with the same period <span>({{T}_{g}} approx {text{174}}.5;{text{years}}.)</span> The lines of the orbital apsides rotate unevenly counterclockwise with the periods of secular rotation <span>({{T}_{{{{g}_{2}}}}} approx 178.3;{text{years}})</span> (for a light planet), and <span>({{T}_{{{{g}_{1}}}}} approx 8140;{text{years}})</span> (for a more massive planet).</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"69 8","pages":"749 - 757"},"PeriodicalIF":0.7,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184137","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":"Second-Degree Local Integral for Rotating Systems. Part II","authors":"F. T. Shamshiev","doi":"10.1134/S1063772925702014","DOIUrl":"10.1134/S1063772925702014","url":null,"abstract":"<p>The study of the existence of the quadratic local integral in stationary two-dimensional potential fields that was initiated in the first part of the work, is continued. New mathematical relationships that deepen the understanding of the structure of functions describing the behavior of potential fields under arbitrary mass distribution have been proposed. The rotation of the coordinate system to simplify the equations and emphasize key features of the functional dependencies has been employed. Particular attention has been paid to arbitrary functions defining the potential and its derivatives under specific conditions. Their properties and possible solutions have been analyzed. Besides, linear differential equations with polynomial and periodic solutions have been studied. Theoretical results, which can be used for further analysis of quadratic integrals and for clarifying the differences between polynomials and other types of functions in broader mathematical models, have been formulated. The paper is partially based on a report presented at the Modern Stellar Astronomy 2024 conference.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"69 8","pages":"766 - 774"},"PeriodicalIF":0.7,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184153","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":"Reasons for the Slow Apsidal Rotation of the Massive Eclipsing Star V1141 Cas","authors":"A. S. Volkova,&nbsp;I. M. Volkov,&nbsp;S. A. Naroenkov","doi":"10.1134/S1063772925701999","DOIUrl":"10.1134/S1063772925701999","url":null,"abstract":"<p>High-precision photometric measurements of the unexplored eclipsing star V1141 Cas (<i>P</i> = 6.909^<i>d</i>, <span>(V{{ = 12.02}^{m}})</span>, <span>(e = 0.37)</span>, Sp B1 V) have shown that the apsidal rotation velocity, <span>({{dot {omega }}_{{{text{obs}}}}} = 0.127^circ )</span>/yr, is two times slower than the theoretical value under the synchronism condition, <span>({{dot {omega }}_{{{text{theor}}}}} = 0.235^circ )</span>/yr. The physical parameters of the component stars were obtained: <span>({{T}_{1}} = 23,500 pm 400)</span> K, <span>({{M}_{1}} = 8.4 pm 0.5{kern 1pt} {{M}_{ odot }})</span>, <span>({{R}_{1}} = 4.24 pm 0.08{kern 1pt} {{R}_{ odot }})</span>, <span>({{T}_{2}} = 22,000 pm 400)</span> K, <span>({{M}_{2}} = 7.0 pm 0.5{kern 1pt} {{M}_{ odot }})</span>, and <span>({{R}_{2}} = 3.38 pm 0.08{kern 1pt} {{R}_{ odot }})</span>. The age of the system is determined to   be 7.5 million years with a solar chemical composition. The measured photometric parallax, <span>(pi =0.00031^{primeprime} pm 0.00004^{primeprime} )</span>, is very close to the Gaia value. The interstellar extinction, <span>({{A}_{{text{V}}}} = {{2.2}^{m}})</span>, is 40 percent higher than the survey’s data.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"69 8","pages":"694 - 707"},"PeriodicalIF":0.7,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184156","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":"On the Encounter Rate of Open Star Clusters","authors":"A. D. Grinenko,&nbsp;D. A. Kovaleva","doi":"10.1134/S1063772925702002","DOIUrl":"10.1134/S1063772925702002","url":null,"abstract":"<p>Probable past and future close encounters of open clusters with known characteristics over 64 m-illion years have been calculated by integrating the orbits of cluster centers in the Galactic potential using the galpy package. It has been shown that in the Galactic neighborhood of the Sun, pairwise cluster encounters at distances comparable to or smaller than their sizes occur at a characteristic rate of 35–40 events per 1 Myr. Close encounters between open clusters with a significant age difference occur at a rate of 15 events per Myr. It can be expected that in the Galaxy as a whole, such events occur an order of magnitude more frequently per unit time. Thus, dynamical interactions between stellar ensembles of different ages may not be too rare and could influence the properties of stellar populations. A pair of clusters with similar ages: HSC 1428 and Gulliver 22 was identified as a likely physically bound binary cluster system. A forecast of expected close encounters over the next 32 Myr has been provided for 490 pairs of clusters. Currently, 29 pairs of clusters are at their closest approach. The paper has been partially based on a report presented at the Modern Stellar Astronomy 2024 conference.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"69 8","pages":"633 - 651"},"PeriodicalIF":0.7,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184155","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":"Transient Narrow High-Velocity Absorptions in the Stationary Spectra of SS 433","authors":"A. V. Dodin,&nbsp;K. A. Postnov,&nbsp;A. M. Cherepashchuk,&nbsp;A. M. Tatarnikov","doi":"10.1134/S1063772925701987","DOIUrl":"10.1134/S1063772925701987","url":null,"abstract":"<p>We report on the discovery of rare emergence (31 nights from 363 nights of observations) of narrow absorption features in hydrogen and helium lines in stationary SS 433 spectra with velocities ranging from ‒650 to –1900 km/s. The components arise independently of the appearance of P Cygni line profiles which are frequently observed in the SS 433 stationary spectra with terminal velocities ranging from –200 to <span>( sim {kern 1pt} - {kern 1pt} 2500)</span> km/s. The characteristic rising time of the transient absorptions is about one day and the decay time is about two days. The phenomenology of the absorptions suggests their origin due to hydrodynamic instabilities of wind outflows from a supercritical accretion disk in SS 433.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"69 8","pages":"685 - 693"},"PeriodicalIF":0.7,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1134/S1063772925701987.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of Recovery Phase Characteristics for Different ICME Polarities (1995–2015)","authors":"W. Alotaibi,&nbsp;B. Badruddin,&nbsp;M. Derouich","doi":"10.1134/S1063772925600207","DOIUrl":"10.1134/S1063772925600207","url":null,"abstract":"<p>Interplanetary coronal mass ejections (ICMEs) are among the main drivers of major geomagnetic storms. The recovery phase of such storms, characterized by a return of geomagnetic indices to pre-disturbance levels, is primarily governed by the decay of the ring current and the cessation of solar wind energy input. This study examines how the characteristics of the recovery phase, specifically the exponential decay time constant (<span>(tau )</span>) of key geomagnetic indices, depend on the polarity configuration of the interplanetary magnetic field (IMF) of the ICMEs. A total of 163 ICME-driven storms from 1995 to 2015 were analyzed using hourly OMNI data. The recovery phase of each storm was modeled with an exponential decay to extract <span>(tau )</span> for the Disturbance Storm Time (Dst) index, Planetary amplitude (ap) index, and Auroral Electrojet (AE) index. Events were categorized into eleven distinct IMF polarity and flux rope configurations to evaluate polarity-dependent recovery behavior. Correlation analyses were also conducted to assess the relationship between <span>(tau )</span> of geomagnetic indices and various solar wind parameters, including IMF <span>({{B}_{z}})</span>, solar wind speed, and coupling functions. Results reveal significant differences in recovery durations across ICME polarity groups. The SN polarity exhibited the fastest Dst recovery (<span>(tau = 18.68 pm 0.80)</span> h), whereas SNS and <span>({{F}^{ + }})</span> configurations exhibited the slowest recoveries (<span>(tau = 43.95 pm 1.27)</span> and <span>(50.97 pm 1.58)</span> h, respectively). For the ap and AE indices, the fastest recovery occurred in NSN (<span>(tau = 4.02 pm 0.46)</span> h) and SNN (<span>(tau = 4.33 pm 0.61)</span> h) configurations, while prolonged recovery was associated with <span>(Fr)</span> (ap) and NSS (AE) events (<span>(tau &gt; 29.90)</span> h). Events dominated by northward magnetic fields recovered significantly faster than those with prolonged southward IMF orientations. Strong statistical coupling was found between <span>(tau )</span>(Dst) and <span>(tau )</span>(ap) (<span>(r = 0.87)</span>), while <span>(tau )</span>(AE) was most sensitive to <span>(n{{E}_{y}})</span> (<span>(r = - 0.52)</span>). Additionally, configurations with small rotation angles (<span>({{F}^{ - }})</span>) recovered more rapidly than those with complex rotations (<span>({{F}^{ + }})</span>), reflecting the role of magnetic structure in sustaining energy input. These findings enhance predictive models of magnetospheric recovery by linking IMF polarity and flux rope topology to the timescales of geomagnetic relaxation.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"69 8","pages":"729 - 748"},"PeriodicalIF":0.7,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184174","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}