Astronomy Reports最新文献_第3页

Search for Weak Components in Pulsar Radiation

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2025-03-14 DOI: 10.1134/S1063772924701014

T. V. Smirnova, M. O. Toropov, S. A. Tyul’bashev

引用次数: 0

Properties of Contracting Massive Protostellar Cores 收缩的大质量原恒星内核的特性

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2025-03-14 DOI: 10.1134/S1063772925701343

L. E. Pirogov, P. M. Zemlyanukha, E. M. Dombek

{"title":"Properties of Contracting Massive Protostellar Cores","authors":"L. E. Pirogov, P. M. Zemlyanukha, E. M. Dombek","doi":"10.1134/S1063772925701343","DOIUrl":"10.1134/S1063772925701343","url":null,"abstract":"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 ( sim {kern 1pt} 1.5{kern 1pt} - {kern 1pt} 2.8). 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.","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}

引用次数: 0

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 以 MASTER OT J044907.58+705812.7 为例，对 MASTER 全球网络望远镜上的一些瞬变现象进行探测和研究

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2025-03-14 DOI: 10.1134/S1063772925701318

V. M. Lipunov, P. V. Balanutsa, E. P. Pavlenko, A. A. Sosnovskij, A. N. Tarasenkov, I. E. Panchenko, K. A. Antonyuk, O. I. Antonyuk, O. A. Gress, A. S. Kuznetsov, K. K. Zhirkov, N. V. Tyurina, A. R. Chasovnikov, G. A. Antipov, E. S. Gorbovskoy, A. N. Yudin, V. V. Topolev, D. V. Cheryasov, D. M. Vlasenko, Y. Kechin, V. A. Senik, A. F. Iyudin, N. M. Budnev, A. G. Tlatov, K. A. Vetrov, M. A. Gulyaev, V. V. Chazov, V. V. Vladimirov, D. S. Zimnukhov

{"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, P. V. Balanutsa, E. P. Pavlenko, A. A. Sosnovskij, A. N. Tarasenkov, I. E. Panchenko, K. A. Antonyuk, O. I. Antonyuk, O. A. Gress, A. S. Kuznetsov, K. K. Zhirkov, N. V. Tyurina, A. R. Chasovnikov, G. A. Antipov, E. S. Gorbovskoy, A. N. Yudin, V. V. Topolev, D. V. Cheryasov, D. M. Vlasenko, Y. Kechin, V. A. Senik, A. F. Iyudin, N. M. Budnev, A. G. Tlatov, K. A. Vetrov, M. A. Gulyaev, V. V. Chazov, V. V. Vladimirov, D. S. Zimnukhov","doi":"10.1134/S1063772925701318","DOIUrl":"10.1134/S1063772925701318","url":null,"abstract":"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 (( > {kern 1pt} {{7}^{m}})), 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.","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}

引用次数: 0

Numerical Study of Polytropes with n = 1 and Differential Rotation

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2025-03-14 DOI: 10.1134/S1063772925701367

T. L. Razinkova, A. V. Yudin, S. I. Blinnikov

引用次数: 0

Influence of Departures from LTE on Determinations of the Sulfur Abundances in A–K Type Stars

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2025-03-14 DOI: 10.1134/S1063772924700987

S. A. Korotin, K. O. Kiselev

{"title":"Influence of Departures from LTE on Determinations of the Sulfur Abundances in A–K Type Stars","authors":"S. A. Korotin, K. O. Kiselev","doi":"10.1134/S1063772924700987","DOIUrl":"10.1134/S1063772924700987","url":null,"abstract":"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 H-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.","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}

引用次数: 0

Third Light in the SS 433 System according to UBVRcIc Photometry 根据 UBVRcIc 光度测定的 SS 433 系统中的第三道亮光

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2025-03-14 DOI: 10.1134/S1063772925701306

A. V. Dodin, A. M. Cherepashchuk, K. A. Postnov, M. A. Burlak, N. P. Ikonnikova

{"title":"Third Light in the SS 433 System according to UBVRcIc Photometry","authors":"A. V. Dodin, A. M. Cherepashchuk, K. A. Postnov, M. A. Burlak, N. P. Ikonnikova","doi":"10.1134/S1063772925701306","DOIUrl":"10.1134/S1063772925701306","url":null,"abstract":"UBVRcIc 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 ({{M}_{ odot }})/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 B filter to 40% in the Ic 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.","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}

引用次数: 0

Fourier Series Methodology for Exploring the Periodic Orbits in the CR3BP with Spherical Primaries

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2025-03-14 DOI: 10.1134/S1063772924600365

Om Prakash Meena, Himanshu Aggarwal, Harsh Mishra, Khush Shaw, Rajiv Aggarwal

引用次数: 0

To the Question of North–South Asymmetry of Solar Activity in the 25th Schwabe–Wolf Cycle

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2025-03-14 DOI: 10.1134/S1063772924701051

S. A. Yazev, E. S. Isaeva, V. M. Tomozov, K. I. Ivanov, B. Hos-Erdene

{"title":"To the Question of North–South Asymmetry of Solar Activity in the 25th Schwabe–Wolf Cycle","authors":"S. A. Yazev, E. S. Isaeva, V. M. Tomozov, K. I. Ivanov, B. Hos-Erdene","doi":"10.1134/S1063772924701051","DOIUrl":"10.1134/S1063772924701051","url":null,"abstract":"An analysis of the north–south asymmetry (NSA) of the groups of sunspots and flares location during the growth phase of the 25th Schwabe–Wolf cycle of solar activity was performed. During the first four years of the cycle’s development, sunspot activity increased quasi-synchronously in the northern and southern hemispheres; the absolute value of the NSA coefficient during this period decreased from 0.6 to 0.2. The longitudinal distribution of sunspots in the second half of 2023 was uneven and similar in both hemispheres; groups of sunspots appeared during this period mainly in the longitudinal intervals of 30°–100°, as well as 200°–280°, while at other longitudes activity was reduced both in the northern and in the southern hemispheres. The number of flares of all classes was 45% in the northern hemisphere, 42% in the southern hemisphere, and 13% were not identified. The flare index was distributed between the hemispheres in the ratio of 49.5 to 42, with 8.5% not identified. A comparison with the 24th cycle shows that NSA in the distribution of sunspots and flares between the northern and southern hemispheres in the current (25th) cycle is significantly lower than in the previous one. A high degree of symmetry of activity can ensure a greater height of the 25th cycle compared to the 24th, as well as the single-peaked nature of the 25th cycle. It is hypothesized that the 25th cycle exhibits a higher level of dipole parity of the global magnetic field compared to the 24th cycle.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1209 - 1216"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622262","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

Analyzing Doublet Type II Radio Bursts During Solar Cycles 23 and 24: Key Characteristics and Trends

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2025-03-14 DOI: 10.1134/S1063772924600316

Charita Pant, Bimal Pande, Raj Kumar, Seema Pande

{"title":"Analyzing Doublet Type II Radio Bursts During Solar Cycles 23 and 24: Key Characteristics and Trends","authors":"Charita Pant, Bimal Pande, Raj Kumar, Seema Pande","doi":"10.1134/S1063772924600316","DOIUrl":"10.1134/S1063772924600316","url":null,"abstract":"This paper presents a statistical analysis of doublet type II radio bursts, specifically the first type II (type II1) and the second type II (type II2), during solar cycles 23 and 24. The study focuses on radio-rich CMEs that are accompanied by type II solar radio bursts, covering a period of 15 years from November 1997 to December 2015. The characteristics of these doublet type II radio bursts were analyzed using data from the Culgoora radio spectrograph. Key parameters such as lifetime, start frequency, end frequency, bandwidth, drift rate, and estimated shock speed (ESS) of both the types of radio burst were examined. During solar cycles 23 and 24, the start frequencies of first type II bursts were generally higher than those of the second type II bursts, suggesting different driving mechanisms for the two types. A good correlation was found between start frequency and drift rate throughout the study period, with correlation coefficients of (r = 0.5) for solar cycle 23 and (r cong 0.9) for solar cycle 24. This indicates that doublet type II radio bursts consistently drift from a high start frequency to a low end frequency, reflecting the rapid propagation of the shock away from the sun. However, the correlation between other solar parameters, such as lifetime, bandwidth, drift rate, and ESS was weak, implying that various drivers or mechanisms might influence the occurrence of these radio bursts. Additionally, the ESS of the first type II bursts was observed to be greater than that of the second type II bursts suggesting that doublet type II radio bursts may originate from eruptions of different structures.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1335 - 1348"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622070","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

Acetylene Trimerization on the Silicon Carbide Surface in the Envelopes of AGB Stars: An Astrochemical Estimation

IF 1.1 4区物理与天体物理

Astronomy Reports Pub Date : 2025-03-14 DOI: 10.1134/S1063772924700999

M. S. Murga

{"title":"Acetylene Trimerization on the Silicon Carbide Surface in the Envelopes of AGB Stars: An Astrochemical Estimation","authors":"M. S. Murga","doi":"10.1134/S1063772924700999","DOIUrl":"10.1134/S1063772924700999","url":null,"abstract":"This work is devoted to estimating the contribution of the trimerization reaction of acetylene molecules on the surface of silicon carbide (SiC) particles with the formation of benzene molecules into the benzene abundance in the envelopes of asymptotic giant branch (AGB) stars. The reaction was included into an astrochemical model, which is used to simulate conditions corresponding to the envelope of the AGB star IRC+10216. The calculation results show that the acetylene trimerization reaction on the SiC surface can effectively occur under the conditions of the envelopes of AGB stars and have a significant effect on the benzene abundance, and, as a consequence, other aromatic molecules. Accounting for acetylene trimerization can increase the benzene abundance in the gas by an order of magnitude. The benzene abundance on the dust surface can be up to four orders of magnitude higher than the estimates for the gas phase predicted by the model with gas-phase reactions only. The rate of benzene formation on the SiC surface significantly exceeds the rate of benzene formation in the gas during the early phases of the star’s pulsation. The efficiency of benzene formation in the trimerization reaction and its transition to gas depends on the currently unknown kinetic parameters of the reaction, in particular, on the desorption energy of the resulting benzene molecule. Determining the reaction parameters will help to perform more accurate quantitative modeling in the future.","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1176 - 1184"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622137","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