New Astronomy最新文献

英文中文

High power accretion in massive binary systems and the impact of metallicity 大质量双星系统的高功率吸积和金属丰度的影响

IF 2.1 4区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

New Astronomy

Pub Date : 2026-01-01 Epub Date: 2025-09-11 DOI: 10.1016/j.newast.2025.102475

Bhawna Mukhija , Amit Kashi

During a giant eruption of a very massive star in the binary system, the companion star can accrete a large amount of mass that can change its properties and potentially its subsequent evolution. The effect depends on the companion mass, metallicity, the amount of mass it accreted, orbital parameters and other parameters. We simulate individual companion stars assuming they undergo such accretion events. We study the envelope properties of 20

M_{⊙}

and 30

M_{⊙}

single massive stars at different metallicities (

Z = 0.02

Z = 0.008

and

Z = 0.004

) during accretion at different rates, from

1 0^{- 5}

1 0^{- 2} M_{⊙} {yr}^{- 1}

. For the lower accretion rates we simulate, the stars remains hot, while at higher accretion rates, it becomes cooler and inflates. This behavior is observed in both stars but occurs at different accretion rates. Higher metallicity stars exhibit greater variations in accretion luminosity for the same accretion rate and stellar mass compared to lower metallicity stars. While higher metallicity stars typically have larger stellar envelopes, suggesting smaller variations in luminosity at Galactic metallicity compared to the LMC and SMC, our results show the opposite.

在双星系统中，一颗质量非常大的恒星爆发时，伴星可以吸积大量的质量，这可能会改变它的性质，并可能改变它随后的演化。这种效应取决于伴星的质量、金属丰度、它所吸积的质量、轨道参数和其他参数。我们模拟单个伴星，假设它们经历了这样的吸积事件。我们研究了不同金属丰度（Z=0.02， Z=0.008和Z=0.004）的20 M⊙和30 M⊙单质量恒星在不同吸积速率（从10−5到10−2M⊙yr−1）下的包层性质。对于我们模拟的较低吸积率，恒星保持热，而在较高的吸积率下，它变得更冷并膨胀。这种行为在两颗恒星中都可以观察到，但发生在不同的吸积速率下。与金属丰度较低的恒星相比，在相同的吸积速率和恒星质量下，金属丰度较高的恒星在吸积光度上表现出更大的变化。虽然金属丰度较高的恒星通常有更大的恒星包层，这表明与LMC和SMC相比，银河系金属丰度的光度变化较小，但我们的结果恰恰相反。

{"title":"High power accretion in massive binary systems and the impact of metallicity","authors":"Bhawna Mukhija , Amit Kashi","doi":"10.1016/j.newast.2025.102475","DOIUrl":"10.1016/j.newast.2025.102475","url":null,"abstract":"<div><div>During a giant eruption of a very massive star in the binary system, the companion star can accrete a large amount of mass that can change its properties and potentially its subsequent evolution. The effect depends on the companion mass, metallicity, the amount of mass it accreted, orbital parameters and other parameters. We simulate individual companion stars assuming they undergo such accretion events. We study the envelope properties of 20 <span><math><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span> and 30 <span><math><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span> single massive stars at different metallicities (<span><math><mrow><mi>Z</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>02</mn></mrow></math></span>, <span><math><mrow><mi>Z</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>008</mn></mrow></math></span> and <span><math><mrow><mi>Z</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>004</mn></mrow></math></span>) during accretion at different rates, from <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>5</mn></mrow></msup></mrow></math></span> to <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup><mspace></mspace><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub><mspace></mspace><msup><mrow><mi>yr</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span>. For the lower accretion rates we simulate, the stars remains hot, while at higher accretion rates, it becomes cooler and inflates. This behavior is observed in both stars but occurs at different accretion rates. Higher metallicity stars exhibit greater variations in accretion luminosity for the same accretion rate and stellar mass compared to lower metallicity stars. While higher metallicity stars typically have larger stellar envelopes, suggesting smaller variations in luminosity at Galactic metallicity compared to the LMC and SMC, our results show the opposite.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"122 ","pages":"Article 102475"},"PeriodicalIF":2.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049122","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

Long-term optical photometry of V709 Cas using TESS: Refined periods and accretion geometry 使用TESS的V709 Cas的长期光学光度测定：精炼周期和吸积几何

IF 2.1 4区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

New Astronomy

Pub Date : 2026-01-01 Epub Date: 2025-10-10 DOI: 10.1016/j.newast.2025.102481

Srinivas M. Rao , Jeewan C. Pandey , Nikita Rawat , Arti Joshi , Ajay Kumar Singh

Utilizing high-cadence and long-term optical photometry from the Transiting Exoplanet Survey Satellite (TESS), we conducted a time-resolved timing analysis of the Intermediate Polar, V709 Cas. Our analysis reveals key characteristics of this system: an orbital period of 5.3329 ± 0.0002 h, a spin period of 312.7478 ± 0.0002 s, and a beat period of 317.9267 ± 0.0002 s. These periods represent a significant refinement over the results of previous studies. These analyses demonstrate that V709 Cas is primarily a disc-overflow accretor, with accretion predominantly occurring via a disc. However, the analysis also reveals epochs where stream-fed accretion is a dominant accretion process. Time-resolved analysis of 20 s short cadence data obtained from sectors 57 and 58 reveals the presence of distinct first harmonics of the spin and beat frequencies. This finding indicates the presence of double peak spin modulation, a characteristic signature of two-pole accretion onto the white dwarf.

利用凌日系外行星巡天卫星（TESS）的高节奏和长期光学光度测量，我们对中极V709 Cas进行了时间分辨时序分析。我们的分析揭示了该系统的主要特征：轨道周期为5.3329±0.0002 h，自旋周期为312.7478±0.0002 s，拍频周期为317.9267±0.0002 s。这些时期代表了对以前研究结果的重大改进。这些分析表明，V709 Cas主要是一个盘溢出吸积体，吸积主要通过盘发生。然而，分析也揭示了以水流吸积为主要吸积过程的时代。对从扇区57和58获得的20秒短节拍数据进行时间分辨分析，发现自旋和拍频存在明显的一阶谐波。这一发现表明存在双峰自旋调制，这是白矮星两极吸积的特征。

引用次数: 0

Numerical study of relativistic jet propagation inside uniform interstellar medium issuing from an Active Galactic Nuclei 活动星系核发出的均匀星际介质内相对论射流传播的数值研究

IF 2.1 4区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

New Astronomy

Pub Date : 2026-01-01 Epub Date: 2025-09-20 DOI: 10.1016/j.newast.2025.102467

Ribhu Pal, Arnab Roy

A direct numerical simulation (DNS) of two-dimensional axisymmetric relativistic jet propagation through a uniform interstellar medium was carried out by solving the relativistic magnetohydrodynamic (RMHD) equations with the PLUTO solver (Mignone et al., 2007). Moreover, a comprehensive discussion of the detailed flow features involved in this propagation is provided throughout this study. The physics underlying shock-vorticity interaction during relativistic jet propagation through a uniform interstellar medium has been thoroughly described in this present study. Additionally, the probability density distribution (p.d.f) of enstrophy (

ϵ

) indicates that the highest intensity of fluid rotation, and consequently turbulence, is manifested within the cocoon instead of the frontal region of the relativistic jet.

利用PLUTO求解器（Mignone et al., 2007）求解相对论磁流体动力学（RMHD）方程，对二维轴对称相对论射流在均匀星际介质中的传播进行了直接数值模拟（DNS）。此外，在整个研究中，还提供了有关这种传播的详细流动特征的全面讨论。本文对相对论性射流在均匀星际介质中传播过程中激波涡度相互作用的物理现象进行了全面的描述。此外，熵（御御）的概率密度分布（p.d.f）表明，最高强度的流体旋转和湍流出现在茧内，而不是在相对论性射流的锋面区域。

引用次数: 0

Out-of-plane equilibria in the Yukawa-type radiating restricted three-body problem (YR3BP) yukawa型辐射受限三体问题的面外平衡

IF 2.1 4区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

New Astronomy

Pub Date : 2026-01-01 Epub Date: 2025-10-03 DOI: 10.1016/j.newast.2025.102480

M. Javed Idrisi, Ruchi Gupta

This study investigates the dynamics of a test particle under the influence of two primaries in the framework of the Yukawa-type radiating restricted three-body problem (YR3BP). The model incorporates two significant perturbations to the classical circular restricted three-body problem (CR3BP): radiation pressure from the larger primary and a Yukawa-type correction to the Newtonian gravitational potential. We first identify the existence and linear stability of out-of-plane equilibrium points, which arise when the radiation pressure exceeds the gravitational pull of the radiating primary. These equilibrium points are found to be independent of the Yukawa parameters, suggesting that the Yukawa-type force does not influence their locations. We also calculate families of three-dimensional periodic (halo-type) and quasi-periodic orbits around these stable equilibrium points using numerical simulations. Our results underline how radiation and modified gravity shape the behaviour of small bodies in disturbed celestial environments, as well as the rich orbital structures that the YR3BP model supports.

本文在汤川型辐射受限三体问题（YR3BP）的框架下，研究了两原色影响下测试粒子的动力学。该模型包含了对经典圆形受限三体问题（CR3BP）的两个重要扰动：来自较大原初的辐射压力和对牛顿引力势的汤川型修正。我们首先确定了当辐射压力超过辐射初级的引力时出现的面外平衡点的存在性和线性稳定性。发现这些平衡点与汤川参数无关，表明汤川型力不影响它们的位置。我们还利用数值模拟计算了围绕这些稳定平衡点的三维周期（晕型）和准周期轨道族。我们的研究结果强调了辐射和修正的重力如何在扰动的天体环境中塑造小天体的行为，以及YR3BP模型所支持的丰富轨道结构。

引用次数: 0

Effects of ion source term on the sheath in electronegative dusty plasmas 离子源项对电负性尘埃等离子体鞘层的影响

IF 2.1 4区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

New Astronomy

Pub Date : 2026-01-01 Epub Date: 2025-09-16 DOI: 10.1016/j.newast.2025.102476

S.A. Galyanseyedi , G. Foroutan , T. Mohsenpour

This study examines a stationary model of the magneto-electronegative dusty plasma sheath, treating dust particles as a cold fluid. In the present model, the electron and negative ion are in Maxwellian thermodynamic equilibrium, while positive ions are considered as a hot fluid with an ion source term. The effects of ion sources and ionization frequencies (IFs) on the sheath are examined to compare their contributions. A modified sheath criterion and floating potential are established theoretically using the Sagdeev potential method. The governing equations of the model are then solved numerically. The effects of the ion source on sheath electric potential, particle density, positive ion velocity, and space charge density are also investigated. It was found that the modified Bohm criterion decreases with an increase of the IF. It can be seen that the different ion source term is effective in the dusty plasma sheath structure.

本研究考察了磁电负性尘埃等离子体鞘的固定模型，将尘埃颗粒视为冷流体。在该模型中，电子和负离子处于麦克斯韦热力学平衡，而正离子被认为是具有离子源项的热流体。离子源和电离频率（if）对鞘的影响进行了检查，比较他们的贡献。利用Sagdeev势法，从理论上建立了改进的鞘层判据和浮动势。然后对模型的控制方程进行了数值求解。研究了离子源对鞘层电位、粒子密度、正离子速度和空间电荷密度的影响。结果表明，修正Bohm准则随IF的增大而减小。可见，不同离子源项在尘埃等离子体鞘层结构中是有效的。

引用次数: 0

Light curve models of convective common envelopes 对流普通包层的光曲线模型

IF 2.1 4区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

New Astronomy

Pub Date : 2026-01-01 Epub Date: 2025-09-27 DOI: 10.1016/j.newast.2025.102477

N. Noughani , J. Nordhaus , M. Richmond , E.C. Wilson

Common envelopes are thought to be the main method for producing tight binaries in the universe as the orbital period shrinks by several orders of magnitude during this phase. Despite their importance for various evolutionary channels, direct detections are rare, and thus observational constraints on common envelope physics are often inferred from post-CE populations. Population constraints suggest that the CE phase must be highly inefficient at using orbital energy to drive envelope ejection for low-mass systems and highly efficient for high-mass systems. Such a dichotomy has been explained by an interplay between convection, radiation and orbital decay. If convective transport to the surface occurs faster than the orbit decays, the CE self-regulates and radiatively cools. Once the orbit shrinks such that convective transport is slow compared to orbital decay, a burst occurs as the release of orbital energy can be far in excess of that required to unbind the envelope. With the anticipation of first light for the Rubin Observatory, we calculate light curve models for convective common envelopes and provide the time evolution of apparent magnitudes for the Rubin filters. Convection imparts a distinct signature in the light curves and lengthens the timescales during which they are observable. Given Rubin limiting magnitudes, convective CEs should be detectable out to distances of

\sim

8 Mpc at a rate of

\sim

0.1 day⁻¹ and provide an intriguing observational test of common envelope physics.

普通的包层被认为是宇宙中产生紧密双星的主要方法，因为轨道周期在这个阶段会缩小几个数量级。尽管它们对各种进化渠道很重要，但直接探测很少，因此对共同包络物理的观测约束通常是从ce后种群中推断出来的。人口约束表明，CE阶段在使用轨道能量驱动包络抛射时，对于低质量系统必须是非常低效的，而对于高质量系统则是非常高效的。这种二分法可以用对流、辐射和轨道衰变之间的相互作用来解释。如果到表面的对流传输比轨道衰减的速度快，CE就会自我调节并进行辐射冷却。一旦轨道收缩到对流传输比轨道衰减慢的程度，就会发生爆发，因为轨道释放的能量可能远远超过解开包络层所需的能量。根据鲁宾天文台第一束光的预期，我们计算了对流共包络的光曲线模型，并提供了鲁宾滤光器视星等的时间演化。对流在光曲线中赋予了一个明显的特征，并延长了它们可观测的时间尺度。考虑到鲁宾极限等，对流ce应该在~ 8 Mpc的距离内以~ 0.1天−1的速率被探测到，并为普通包膜物理提供了一个有趣的观测测试。

{"title":"Light curve models of convective common envelopes","authors":"N. Noughani , J. Nordhaus , M. Richmond , E.C. Wilson","doi":"10.1016/j.newast.2025.102477","DOIUrl":"10.1016/j.newast.2025.102477","url":null,"abstract":"<div><div>Common envelopes are thought to be the main method for producing tight binaries in the universe as the orbital period shrinks by several orders of magnitude during this phase. Despite their importance for various evolutionary channels, direct detections are rare, and thus observational constraints on common envelope physics are often inferred from post-CE populations. Population constraints suggest that the CE phase must be highly inefficient at using orbital energy to drive envelope ejection for low-mass systems and highly efficient for high-mass systems. Such a dichotomy has been explained by an interplay between convection, radiation and orbital decay. If convective transport to the surface occurs faster than the orbit decays, the CE self-regulates and radiatively cools. Once the orbit shrinks such that convective transport is slow compared to orbital decay, a burst occurs as the release of orbital energy can be far in excess of that required to unbind the envelope. With the anticipation of first light for the Rubin Observatory, we calculate light curve models for convective common envelopes and provide the time evolution of apparent magnitudes for the Rubin filters. Convection imparts a distinct signature in the light curves and lengthens the timescales during which they are observable. Given Rubin limiting magnitudes, convective CEs should be detectable out to distances of <span><math><mo>∼</mo></math></span> 8 Mpc at a rate of <span><math><mo>∼</mo></math></span> 0.1 day<sup>−1</sup> and provide an intriguing observational test of common envelope physics.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"122 ","pages":"Article 102477"},"PeriodicalIF":2.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145332742","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

Dataset of artefacts for machine learning applications in astronomy 天文学中机器学习应用的人工制品数据集

IF 2.1 4区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

New Astronomy

Pub Date : 2026-01-01 Epub Date: 2025-08-29 DOI: 10.1016/j.newast.2025.102466

Sreevarsha Sreejith , Maria V. Pruzhinskaya , Alina A. Volnova , Vadim V. Krushinsky , Konstantin L. Malanchev , Emille E.O. Ishida , Anastasia D. Lavrukhina , Timofey A. Semenikhin , Emmanuel Gangler , Matwey V. Kornilov , Vladimir S. Korolev

Accurate photometry in astronomical surveys is challenged by image artefacts, which affect measurements and degrade data quality. Due to the large amount of available data, this task is increasingly handled using machine learning algorithms, which often require a labelled training set to learn data patterns. We present an expert-labelled dataset of 1127 artefacts with 1213 labels from 26 fields in ZTF DR3, along with a complementary set of nominal objects. The artefact dataset was compiled using the active anomaly detection algorithm PineForest, developed by the SNAD team. These datasets can serve as valuable resources for real-bogus classification, catalogue cleaning, anomaly detection, and educational purposes. Both artefacts and nominal images are provided in FITS format in two sizes (28 × 28 and 63 × 63 pixels). The datasets are publicly available for further scientific applications.

在天文调查中，精确的光度测量受到图像伪影的挑战，这些伪影会影响测量结果并降低数据质量。由于大量的可用数据，这项任务越来越多地使用机器学习算法来处理，这通常需要一个标记的训练集来学习数据模式。我们提出了一个专家标记的数据集，包含来自ZTF DR3中26个领域的1127个人工制品和1213个标签，以及一组补充的标称对象。人工数据集使用SNAD团队开发的主动异常检测算法pinefforest进行编译。这些数据集可以作为真假分类、目录清理、异常检测和教育目的的宝贵资源。人工制品和标称图像都以FITS格式提供，有两种尺寸（28 × 28和63 × 63像素）。这些数据集是公开的，可用于进一步的科学应用。

{"title":"Dataset of artefacts for machine learning applications in astronomy","authors":"Sreevarsha Sreejith , Maria V. Pruzhinskaya , Alina A. Volnova , Vadim V. Krushinsky , Konstantin L. Malanchev , Emille E.O. Ishida , Anastasia D. Lavrukhina , Timofey A. Semenikhin , Emmanuel Gangler , Matwey V. Kornilov , Vladimir S. Korolev","doi":"10.1016/j.newast.2025.102466","DOIUrl":"10.1016/j.newast.2025.102466","url":null,"abstract":"<div><div>Accurate photometry in astronomical surveys is challenged by image artefacts, which affect measurements and degrade data quality. Due to the large amount of available data, this task is increasingly handled using machine learning algorithms, which often require a labelled training set to learn data patterns. We present an expert-labelled dataset of 1127 artefacts with 1213 labels from 26 fields in ZTF DR3, along with a complementary set of nominal objects. The artefact dataset was compiled using the active anomaly detection algorithm <span>PineForest</span>, developed by the SNAD team. These datasets can serve as valuable resources for real-bogus classification, catalogue cleaning, anomaly detection, and educational purposes. Both artefacts and nominal images are provided in FITS format in two sizes (28 × 28 and 63 × 63 pixels). The datasets are publicly available for further scientific applications.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"122 ","pages":"Article 102466"},"PeriodicalIF":2.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020441","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

Mass–radius relationship of strongly magnetized deformed white dwarfs 强磁化变形白矮星的质量-半径关系

IF 1.9 4区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

New Astronomy

Pub Date : 2025-12-01 Epub Date: 2025-07-02 DOI: 10.1016/j.newast.2025.102450

Rajasmita Sahoo , Tambe Pranjal Anant , Somnath Mukhopadhyay

The masses and radii of strongly magnetized anisotropic deformed white dwarf stars are investigated using the stellar structure equations in the parameterized

γ

-metric formalism. The Equation of State (EoS) of a completely degenerate relativistic electron gas in strong quantizing density-dependent magnetic field is developed. The fluid and field pressure anisotropy among the parallel and perpendicular components to the magnetic field is taken into consideration. This anisotropy in the EoS causes axisymmetric deformation of the star. We found stable solutions of deformed super-Chandrasekhar ultramassive white dwarfs. At a fixed central electron number density, the mass first increases from the traditional Chandrasekhar limit with increase of central magnetic field strength, reaches a maximum and then decreases with further increase of central magnetic field. For lower central magnetic field strengths, both the pressure anisotropy and the resulting deformation are very less, and hence the mass increases. In the higher central magnetic field regime, the magnetic field pressure anisotropy becomes significantly strong. This leads to greater deformation from spherical symmetry and hence reduces the stellar mass. We also see that the maximum mass and its corresponding equatorial radius both decrease as central magnetic field strength increases. We also notice that the maximum mass occurs at higher central density as the magnetic field increases. These phenomena also occur because of the deviation from spherical symmetry due to higher pressure anisotropy. High magnetic field increases stellar compactness.

利用参数化γ-度量形式的恒星结构方程，研究了强磁化各向异性变形白矮星的质量和半径。建立了强量子化密度相关磁场中完全简并相对论性电子气体的态方程。考虑了磁场平行分量和垂直分量的流体和场压力各向异性。EoS的这种各向异性导致了恒星的轴对称变形。我们找到了变形的超级钱德拉塞卡超大质量白矮星的稳定解。在一定的中心电子数密度下，随着中心磁场强度的增加，质量首先从传统的钱德拉塞卡极限开始增加，达到最大值，然后随着中心磁场的进一步增加而减小。当中心磁场强度较低时，压力各向异性和产生的变形都很小，因此质量增加。在较高的中心磁场区，磁场压力各向异性明显增强。这导致了更大的球面对称变形，从而减少了恒星质量。我们还看到，随着中心磁场强度的增加，最大质量及其相应的赤道半径都减小。我们还注意到，随着磁场的增加，最大质量出现在较高的中心密度处。这些现象也会发生，因为压力各向异性较高而偏离了球对称。高磁场增加了恒星的致密性。

{"title":"Mass–radius relationship of strongly magnetized deformed white dwarfs","authors":"Rajasmita Sahoo , Tambe Pranjal Anant , Somnath Mukhopadhyay","doi":"10.1016/j.newast.2025.102450","DOIUrl":"10.1016/j.newast.2025.102450","url":null,"abstract":"<div><div>The masses and radii of strongly magnetized anisotropic deformed white dwarf stars are investigated using the stellar structure equations in the parameterized <span><math><mi>γ</mi></math></span>-metric formalism. The Equation of State (EoS) of a completely degenerate relativistic electron gas in strong quantizing density-dependent magnetic field is developed. The fluid and field pressure anisotropy among the parallel and perpendicular components to the magnetic field is taken into consideration. This anisotropy in the EoS causes axisymmetric deformation of the star. We found stable solutions of deformed super-Chandrasekhar ultramassive white dwarfs. At a fixed central electron number density, the mass first increases from the traditional Chandrasekhar limit with increase of central magnetic field strength, reaches a maximum and then decreases with further increase of central magnetic field. For lower central magnetic field strengths, both the pressure anisotropy and the resulting deformation are very less, and hence the mass increases. In the higher central magnetic field regime, the magnetic field pressure anisotropy becomes significantly strong. This leads to greater deformation from spherical symmetry and hence reduces the stellar mass. We also see that the maximum mass and its corresponding equatorial radius both decrease as central magnetic field strength increases. We also notice that the maximum mass occurs at higher central density as the magnetic field increases. These phenomena also occur because of the deviation from spherical symmetry due to higher pressure anisotropy. High magnetic field increases stellar compactness.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"121 ","pages":"Article 102450"},"PeriodicalIF":1.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144580360","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

Non-singular bounce scenario of Higher dimensional dark energy cosmological model in Lyra geometry 天琴座几何中高维暗能量宇宙模型的非奇异弹跳情形

IF 2.1 4区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

New Astronomy

Pub Date : 2025-12-01 Epub Date: 2025-08-20 DOI: 10.1016/j.newast.2025.102464

Kangujam Priyokumar Singh, Asem Jotin Meitei

In this work, we examine a five-dimensional anisotropic Bianchi type III cosmological model within the framework of Lyra geometry. We investigate the matter bounce scenario under the dark energy condition for the equation of state relationship

ρ = W p

with

W = - 1

. Utilizing the energy–momentum tensor of a perfect fluid, we derive the solution for the model universe. Our proposed model also evaluates the behavior of energy conditions, state-finders, the current value of the deceleration parameter and stability conditions.

在这项工作中，我们在天琴座几何的框架内研究了一个五维各向异性的Bianchi III型宇宙学模型。我们研究了在暗能量条件下，ρ=Wp， W= - 1的状态关系方程下的物质弹跳情形。利用完美流体的能量动量张量，我们推导出模型宇宙的解。我们提出的模型还评估了能量条件、状态检测器、减速参数的当前值和稳定性条件的行为。

引用次数: 0

In-depth analysis of the light curve and first orbital period of contact binary GM Dra 深入分析了接触双星GM - Dra的光曲线和第一轨道周期

IF 1.9 4区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

New Astronomy

Pub Date : 2025-12-01 Epub Date: 2025-06-25 DOI: 10.1016/j.newast.2025.102445

M.F. Yıldırım

This study presents the light curve (LC) analysis of the GM Dra eclipsing binary (using data from TESS, SuperWASP, KWS(

I_{c}

), Hipparcos, and ASAS-SN), along with a detailed investigation of its orbital period (OP) for the first time. Photometric data obtained from five different databases were used to simultaneously analyze the system’s LC and radial velocity (RV). The LC modeling results for GM Dra reveal the object stars’ masses and radii as follows:

M_{1} = 0.28 \pm 0.01

_{⊙}

M_{2} = 1.34 \pm 0.02

_{⊙}

R_{1} = 0.64 \pm 0.01

_{⊙}

, and

R_{2} = 1.27 \pm 0.02

_{⊙}

. A total of 108 eclipse times (ETs) were calculated on the basis of TESS and SuperWASP observations. These ETs are of great significance in determining the OP change. The OP of the GM Dra has been analyzed based on long-term observations, revealing that the OP of GM Dra is decreasing by 0.051 s per year. A sinusoidal variation in the period change was also identified, which may be attributed to the presence of a potential third object or magnetic activity. These findings provide significant insights into the evolutionary status (the positions of the system in the Hertzsprung–Russell (HR) diagram and logM

_{t o t .}

–logJ diagram were discussed) of GM Dra and the dynamics of the binary system.

本文首次利用TESS、SuperWASP、KWS（Ic）、Hipparcos和ASAS-SN卫星的数据，对GM Dra食双星进行了光曲线（LC）分析，并对其轨道周期（OP）进行了详细的研究。从五个不同的数据库中获得的光度数据同时用于分析系统的LC和径向速度（RV）。对GM Dra的LC建模结果显示，目标恒星的质量和半径分别为：M1=0.28±0.01 M⊙,M2=1.34±0.02 M⊙,R1=0.64±0.01 R⊙,R2=1.27±0.02 R⊙。根据TESS和SuperWASP的观测结果，共计算了108次日食次数。这些ETs对于确定OP变化具有重要意义。在长期观测的基础上，对青藏高原的OP进行了分析，结果表明，青藏高原的OP以每年0.051 s的速度递减。周期变化的正弦变化也被确定，这可能归因于潜在的第三个物体或磁活动的存在。这些发现对进化状态（系统在赫茨普龙-罗素（HR）图和logMtot中的位置）提供了重要的见解。讨论了GM - Dra的-logJ图和二元体系的动力学。

{"title":"In-depth analysis of the light curve and first orbital period of contact binary GM Dra","authors":"M.F. Yıldırım","doi":"10.1016/j.newast.2025.102445","DOIUrl":"10.1016/j.newast.2025.102445","url":null,"abstract":"<div><div>This study presents the light curve (LC) analysis of the GM Dra eclipsing binary (using data from TESS, SuperWASP, KWS(<span><math><msub><mrow><mi>I</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>), Hipparcos, and ASAS-SN), along with a detailed investigation of its orbital period (OP) for the first time. Photometric data obtained from five different databases were used to simultaneously analyze the system’s LC and radial velocity (RV). The LC modeling results for GM Dra reveal the object stars’ masses and radii as follows: <span><math><mrow><msub><mrow><mi>M</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>=</mo><mn>0</mn><mo>.</mo><mn>28</mn><mo>±</mo><mn>0</mn><mo>.</mo><mn>01</mn></mrow></math></span> M<span><math><msub><mrow></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>, <span><math><mrow><msub><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>=</mo><mn>1</mn><mo>.</mo><mn>34</mn><mo>±</mo><mn>0</mn><mo>.</mo><mn>02</mn></mrow></math></span> M<span><math><msub><mrow></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>, <span><math><mrow><msub><mrow><mi>R</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>=</mo><mn>0</mn><mo>.</mo><mn>64</mn><mo>±</mo><mn>0</mn><mo>.</mo><mn>01</mn></mrow></math></span> R<span><math><msub><mrow></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>, and <span><math><mrow><msub><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>=</mo><mn>1</mn><mo>.</mo><mn>27</mn><mo>±</mo><mn>0</mn><mo>.</mo><mn>02</mn></mrow></math></span> R<span><math><msub><mrow></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>. A total of 108 eclipse times (ETs) were calculated on the basis of TESS and SuperWASP observations. These ETs are of great significance in determining the OP change. The OP of the GM Dra has been analyzed based on long-term observations, revealing that the OP of GM Dra is decreasing by 0.051 s per year. A sinusoidal variation in the period change was also identified, which may be attributed to the presence of a potential third object or magnetic activity. These findings provide significant insights into the evolutionary status (the positions of the system in the Hertzsprung–Russell (HR) diagram and logM<span><math><msub><mrow></mrow><mrow><mi>t</mi><mi>o</mi><mi>t</mi><mo>.</mo></mrow></msub></math></span>–logJ diagram were discussed) of GM Dra and the dynamics of the binary system.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"121 ","pages":"Article 102445"},"PeriodicalIF":1.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144480598","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

首页上一页

下一页尾页

类型

全部化学•材料生命科学医学物理工程技术环境•农林材料科学地球科学法学管理学化学环境科学与生态学计算机科学教育学经济学农林科学人文科学生物学数学物理与天体物理心理学综合性期刊其他工业工程理学历史学农学文学信息工程

数据库

全部 ACS Publications Elsevier ieeexplore Springer The Royal Society of Chemistry Wiley

期刊

New Astronomy

全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.

﹀