Astrophysics最新文献

Correction: Effective Potentials in General Scalar-Tensor Theories of Gravity 修正：一般引力标量张量理论中的有效势

IF 0.7 4区物理与天体物理

Astrophysics Pub Date : 2026-04-28 DOI: 10.1007/s10511-026-09912-6

A. A. Saharian, G. H. Harutyunyan, H. K. Teryan, R. M. Avagyan

引用次数: 0

Correction: A Study on Geodesics and Lifespan of the Rindler-Modified Schwarzschild Black Hole. II. Null Geodesics and Black Hole Lifespan 修正：关于rindler修正史瓦西黑洞的测地线和寿命的研究。2。零测地线和黑洞寿命

IF 0.7 4区物理与天体物理

Astrophysics Pub Date : 2026-04-28 DOI: 10.1007/s10511-026-09911-7

T. Huo, C. Liu

引用次数: 0

Dynamics of Bouncing Cosmology in Brans-Dicke Gravity with Kaniadakis Holographic Dark Energy 基于卡尼达基斯全息暗能量的Brans-Dicke引力弹跳宇宙学动力学

IF 0.7 4区物理与天体物理

Astrophysics Pub Date : 2026-04-23 DOI: 10.1007/s10511-026-09909-1

K. Murali, Y. Aditya, S. K. Vali

{"title":"Dynamics of Bouncing Cosmology in Brans-Dicke Gravity with Kaniadakis Holographic Dark Energy","authors":"K. Murali, Y. Aditya, S. K. Vali","doi":"10.1007/s10511-026-09909-1","DOIUrl":"10.1007/s10511-026-09909-1","url":null,"abstract":"We examine bouncing cosmology in the anisotropic Bianchi type-III framework within Brans-Dicke gravity, incorporating Kaniadakis holographic dark energy with Hubble and Granda-Oliveros radii as infrared cutoff. We reconstruct bouncing model through correspondence scheme utilizing power-law form of the scalar field in terms of average scale factor. The natural anisotropy in Bianchi type-III model modifies expansion dynamics, offering a broader perspective on early-universe evolution beyond standard isotropic models. We analyze key cosmological parameters, including deceleration, jerk, equation of state ωde , energy conditions, squared sound speed ({upsilon }_{s}^{2}) and ({{omega }_{de}-omega }_{de}{prime}) plane. Models are exhibiting oscillatory transitions across the phantom divide and evolves smoothly toward ωde at late times. The stability analysis based on the squared sound speed ({upsilon }_{s}^{2}) reveals that models remain dynamically stable over most of the cosmic history and admit instabilities near the bounce. A dynamical phase-space study in the ({{omega }_{de}-omega }_{de}{prime}) plane shows that both models evolve predominantly in the thawing region, implying an asymptotic approach to a cosmological constant. The energy condition analysis further confirms that the violation of the null and strong energy conditions is a necessary feature for the realization of the bounce.","PeriodicalId":479,"journal":{"name":"Astrophysics","volume":"68 4","pages":"664 - 690"},"PeriodicalIF":0.7,"publicationDate":"2026-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147828578","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

Starspot Activity of Moving Groups from Tess Mission Archive Data 来自Tess任务档案数据的移动群的恒星黑子活动

IF 0.7 4区物理与天体物理

Astrophysics Pub Date : 2026-04-23 DOI: 10.1007/s10511-026-09899-0

I. S. Savanov, N. E. Kondratev

引用次数: 0

On the Origin of Emission in the White-Light Continuum in Powerful Stellar and Solar Flares 强恒星和太阳耀斑中白光连续体发射源的研究

IF 0.7 4区物理与天体物理

Astrophysics Pub Date : 2026-04-23 DOI: 10.1007/s10511-026-09906-4

E. S. Morchenko

引用次数: 0

Asteroid Rotation Periods: Statistical Analysis in the Diameterspin Distribution 小行星自转周期：直径自旋分布的统计分析

IF 0.7 4区物理与天体物理

Astrophysics Pub Date : 2026-04-23 DOI: 10.1007/s10511-026-09905-5

M. Nastaran, A. Poro, R. Hosseini, M. Najarzadeh

引用次数: 0

Computational Analysis of Resonant Structures in p7Be Scattering and Their Correlation with the Astrophysical S-Factor p7Be散射共振结构的计算分析及其与天体物理s因子的相关性

IF 0.7 4区物理与天体物理

Astrophysics Pub Date : 2026-04-23 DOI: 10.1007/s10511-026-09908-2

A. Khachi, V. Dwivedi, S. Awasthi

引用次数: 0

Determination of Starspot Coverage of Solar-Type Stars with Superflares 用超级耀斑测定太阳型恒星的星斑覆盖率

IF 0.7 4区物理与天体物理

Astrophysics Pub Date : 2026-04-23 DOI: 10.1007/s10511-026-09904-6

A. A. Akopian

{"title":"Determination of Starspot Coverage of Solar-Type Stars with Superflares","authors":"A. A. Akopian","doi":"10.1007/s10511-026-09904-6","DOIUrl":"10.1007/s10511-026-09904-6","url":null,"abstract":"The paper addresses the problem of determining the degree of starspot coverage of solar-type stars producing superflares, using a method previously developed by the author to estimate the spottedness of flaring stars based on the chronology of recorded flares. The method involves determining a periodic function of flare rate using statistical analysis of time series. The latter are interpreted as a Poisson process with a cyclic parameter associated with the stellar rotation period. Transformation of this function into the von Mises probability density function of circular distribution shifts the perspective from flare frequency to the angular distribution of starspots and determining the effective surface area covered by spots. Nine of the most active solar-type stars from the catalog of Okamoto et al. were investigated. For these stars, rotation periods were calculated using flare chronology, concentration parameters of the flare distribution were determined, and angular distributions of starspot coverage were obtained. The estimated degrees of spottedness range from 1–4% for minimally spotted hemispheres to up to 10% for maximally spotted hemispheres, which significantly exceeds the corresponding values for the Sun. Comparison with the results of Okamoto et al. demonstrates a high degree of agreement, with a correlation coefficient r = 0.896. The developed approach enables determining stellar spottedness based solely on time series of flare activity without the use of high-resolution photometric or spectroscopic data, making it a valuable tool for statistical studies of magnetic activity in solar-type stars exhibiting superflares.","PeriodicalId":479,"journal":{"name":"Astrophysics","volume":"68 4","pages":"604 - 614"},"PeriodicalIF":0.7,"publicationDate":"2026-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147828587","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

Theoretical Investigation of Dark Stars Admitting the Chaplygin Equation of State 承认Chaplygin状态方程的暗星理论研究

IF 0.7 4区物理与天体物理

Astrophysics Pub Date : 2026-04-23 DOI: 10.1007/s10511-026-09910-8

P. Tamta, P. Fuloria

{"title":"Theoretical Investigation of Dark Stars Admitting the Chaplygin Equation of State","authors":"P. Tamta, P. Fuloria","doi":"10.1007/s10511-026-09910-8","DOIUrl":"10.1007/s10511-026-09910-8","url":null,"abstract":"This study investigates the internal structure of compact stars models using the Chaplygin equation of state, a notable candidate for describing exotic matter due to its ability to manifest dark energy through an inverse pressure-density relationship. By integrating this equation of state into the framework of general relativity, we derive solutions that describe stable and physically realistic stellar configurations. The spacetime geometry within the stellar interior is governed by the Buchdahl metric potential, facilitating the construction of analytic models applicable to observed compact objects such as PSRJ1903 + 327, CenX - 3, and VelaX - 1, with respective masses of 1.667 M⊙ , 1.49 M⊙ , and 1.77 M⊙ , and corresponding radii of 9.438 km, 9.178 km, and 9.56 km. To visualize the behavior of thermodynamic variables, two-dimensional contour plots are employed to illustrate the spatial variation of matter density and radial pressure, revealing centrally peaked distributions that decrease smoothly toward the boundary-consistent with expected stellar behavior. The model's validity is further examined using standard physical checks, including the satisfaction of energy conditions, causality constraints, and dynamical stability via the adiabatic index. The results support the Chaplygin gas as a compelling equation of state for describing compact astrophysical bodies and demonstrate the effectiveness of combining analytic methods with advanced graphical analysis in modeling relativistic stars.","PeriodicalId":479,"journal":{"name":"Astrophysics","volume":"68 4","pages":"691 - 715"},"PeriodicalIF":0.7,"publicationDate":"2026-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147828582","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

Are Some Chemically Peculiar Stars that Show Strong Overabundances of Very Heavy Elements Related to Supernovae? 一些化学上特殊的恒星是否显示出与超新星有关的重元素的强烈过剩？

IF 0.7 4区物理与天体物理

Astrophysics Pub Date : 2026-04-21 DOI: 10.1007/s10511-026-09903-7

S. Ghazaryan, G. Alecian

{"title":"Are Some Chemically Peculiar Stars that Show Strong Overabundances of Very Heavy Elements Related to Supernovae?","authors":"S. Ghazaryan, G. Alecian","doi":"10.1007/s10511-026-09903-7","DOIUrl":"10.1007/s10511-026-09903-7","url":null,"abstract":"For many years, detailed observational and statistical study of the chemically peculiar stars showed that the presence of heavy radioactive chemical elements overabundances in their atmospheres are not well understood. We try to explain the overabundance of a few of them by the explosion of the possible supernovae in binary or multiple stellar system, i.e. to search for a chemically peculiar star and pulsar pair by traceback motion study in the Galaxy. We analyzed trajectories of 529 chemically peculiar stars of our sample and 28 pulsars from ATNF catalogue, which ages do not exceed 100 Myr, and obtained several possible candidate pairs (CP star plus pulsar), which may have been at the same place at the same time. Moreover, our traceback study of them with the young stellar clusters (Hunt and Reffert, 2023) led to the identification of several, possibly, parental stellar groups. Furthermore, more detailed studies are needed to estimate the ages of chemically peculiar stars and detect their locations of formation, as well as use statistical methods to assess whether the possible supernova ejection is the result of coincidence or not. Obviously, modeling of the best chemically peculiar star-pulsar pairs will also allow us to explain the processes occurring in these stars.","PeriodicalId":479,"journal":{"name":"Astrophysics","volume":"68 4","pages":"594 - 603"},"PeriodicalIF":0.7,"publicationDate":"2026-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147828585","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