The Astrophysical Journal最新文献_第7页

Strong Photospheric Heating Indicated by Fe i 6173 Å Line Emission during White-light Solar Flares fei 6173 Å白光太阳耀斑期间的线发射所指示的强光球加热

The Astrophysical Journal Pub Date : 2025-07-14 DOI: 10.3847/1538-4357/addd1e

Samuel Granovsky, Alexander G. Kosovichev, Viacheslav M. Sadykov, Graham S. Kerr and Joel C. Allred

{"title":"Strong Photospheric Heating Indicated by Fe i 6173 Å Line Emission during White-light Solar Flares","authors":"Samuel Granovsky, Alexander G. Kosovichev, Viacheslav M. Sadykov, Graham S. Kerr and Joel C. Allred","doi":"10.3847/1538-4357/addd1e","DOIUrl":"https://doi.org/10.3847/1538-4357/addd1e","url":null,"abstract":"Between 2017 and 2024, the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory has observed numerous white-light solar flares (WLFs). HMI spectropolarimetric observations of certain WLFs, in particular the X9.3 flare of 2017 September 6, reveal one or more locations within the umbra or along the umbra/penumbra boundary of the flaring active region where the Fe I 6173 Å line briefly goes into full emission, indicating significant heating of the photosphere and lower chromosphere. For five flares featuring Fe I 6173 Å line-core emission, we perform spectropolarimetric analysis using HMI 90 s cadence Stokes data. For all investigated flares, line-core emission is observed to last for a single 90 s frame and is either concurrent with or followed by an increase in the line continuum intensity lasting one to two frames (90–180 s). Additionally, permanent changes to the Stokes Q, U, and/or V profiles were observed, indicating long-lasting nontransient changes to the photospheric magnetic field. These emissions coincided with local maxima in hard X-ray emission observed by Konus-Wind, as well as local maxima in the time derivative of soft X-ray emission observed by GOES 16-18. Comparison of the Fe I 6173 Å line profile synthesis for the ad hoc heating of the initial empirical VAL-S umbra model and quiescent-Sun (VAL-C-like) model indicates that the Fe I 6173 Å line emission in the white-light flare kernels could be explained by the strong heating of initially cool photospheric regions.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"99 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144630153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Where is the Supervirial Gas? The Supply from Hot Inflows 环境气体在哪里？热流入的供给

The Astrophysical Journal Pub Date : 2025-07-14 DOI: 10.3847/1538-4357/ade059

Manami Roy, Kung-Yi Su, Smita Mathur and Jonathan Stern

{"title":"Where is the Supervirial Gas? The Supply from Hot Inflows","authors":"Manami Roy, Kung-Yi Su, Smita Mathur and Jonathan Stern","doi":"10.3847/1538-4357/ade059","DOIUrl":"https://doi.org/10.3847/1538-4357/ade059","url":null,"abstract":"To understand the presence of the supervirial temperature gas detected in the Milky Way (MW), we present our findings from isolated galaxy simulations of MW-mass systems using GIZMO with the Feedback in Realistic Environments (FIRE-2) stellar feedback model. It unveils the presence of a significant supervirial temperature (T > Tvir) gas component within 20 kpc from the galactic center. We also find that 70%–90% of the total supervirial gas is extraplanar, at 1 < z < 6 kpc and Rcyl < 15 kpc. This supervirial gas has a mass of 1−2 × 107M⊙ with typical gas densities are 10−3.5−10−2.5 cm−3. We find that some of the virial gas (T ∼ 106 K) forms a rotating hot inflow, where gravitational energy is converted to thermal energy mainly via compressive heating. This process causes gas falling close to the rotation axis to reach supervirial temperatures via a combination of compressive heating and shocks just before cooling and joining the disk. Stellar feedback heating accounts for less than 1% of the supervirial gas, indicating its minimal influence despite expectations. Even in scenarios with no stellar feedback effects considered, abundant supervirial gas persists, highlighting the dominance of alternative heating mechanisms. We also show that cosmic rays do not have a significant effect on heating the gas to a supervirial temperature. Our study illuminates the intricate dynamics of hot virial and supervirial gas surrounding MW-mass galaxies, emphasizing the prominent role of infall-driven compressive and shock-heating processes in shaping thermal evolution.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144630331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Growth and Decay of Individual Sunspots and Pores 单个太阳黑子和毛孔的生长和衰减

The Astrophysical Journal Pub Date : 2025-07-14 DOI: 10.3847/1538-4357/ade790

Andrei G. Tlatov

引用次数: 0

A Catalog of Galactic Supernova Remnants and Supernova Remnant Candidates from the EMU/POSSUM Radio Sky Surveys. I. 来自EMU/POSSUM射电巡天的银河系超新星遗迹和候选超新星遗迹目录。我。

The Astrophysical Journal Pub Date : 2025-07-14 DOI: 10.3847/1538-4357/addc63

B. D. Ball, R. Kothes, E. Rosolowsky, C. Burger-Scheidlin, M. D. Filipović, S. Lazarević, Z. J. Smeaton, W. Becker, E. Carretti, B. M. Gaensler, A. M. Hopkins, D. Leahy, M. Tahani, J. L. West, C. S. Anderson, S. Loru, Y. K. Ma, N. M. McClure-Griffiths and M. J. Michałowski

{"title":"A Catalog of Galactic Supernova Remnants and Supernova Remnant Candidates from the EMU/POSSUM Radio Sky Surveys. I.","authors":"B. D. Ball, R. Kothes, E. Rosolowsky, C. Burger-Scheidlin, M. D. Filipović, S. Lazarević, Z. J. Smeaton, W. Becker, E. Carretti, B. M. Gaensler, A. M. Hopkins, D. Leahy, M. Tahani, J. L. West, C. S. Anderson, S. Loru, Y. K. Ma, N. M. McClure-Griffiths and M. J. Michałowski","doi":"10.3847/1538-4357/addc63","DOIUrl":"https://doi.org/10.3847/1538-4357/addc63","url":null,"abstract":"We use data from the Evolutionary Map of the Universe (EMU) and Polarization Sky Survey of the Universe’s Magnetism (POSSUM) radio southern sky surveys, conducted with the Australian Square Kilometre Array Pathfinder (ASKAP) to compile a catalog of Galactic supernova remnants (SNRs) and candidate SNRs within the region of 277 5 ≤ ℓ ≤ 311 7 Galactic longitude, ∣b∣ ≤ 5 4 Galactic latitude, as well as an additional field along the Galactic plane, approximately 315 5 ≤ ℓ ≤ 323 0 Galactic longitude, −4.5 ≤ b ≤ 1.5 Galactic latitude. In the areas studied, there are 44 known SNRs and 46 SNR candidates that have been previously identified in the radio. We confirm eight of these candidates as SNRs based on evidence of linear polarization or through the calculation of nonthermal spectral indices. Additionally, we identify possible radio counterparts for seven SNR candidates that were previously only identified in X-rays (four) or optical (three). We also present six new SNRs and 37 new SNR candidates. The results of this study demonstrate the utility of ASKAP for discovering new and potential SNRs and refining the classification of previously identified candidates. In particular, we find that the EMU and POSSUM surveys are particularly well suited for observing high-latitude SNRs and confirming SNR candidates with polarization. The region studied in this work represents approximately one-quarter of the Galactic plane, by longitude, that will eventually be surveyed by EMU/POSSUM, and we expect that the ongoing surveys will continue to uncover new SNRs and SNR candidates.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144629953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fundamental Parameters for Totally Eclipsing Contact Binaries Observed by TESS TESS观测到的全食接触双星基本参数

The Astrophysical Journal Pub Date : 2025-07-14 DOI: 10.3847/1538-4357/addfcf

Xu Ding, KaiFan Ji, ZhiMing Song, XueFen Tian, JinLiang Wang, ChuanJun Wang, QiYuan Cheng and JianPing Xiong

{"title":"Fundamental Parameters for Totally Eclipsing Contact Binaries Observed by TESS","authors":"Xu Ding, KaiFan Ji, ZhiMing Song, XueFen Tian, JinLiang Wang, ChuanJun Wang, QiYuan Cheng and JianPing Xiong","doi":"10.3847/1538-4357/addfcf","DOIUrl":"https://doi.org/10.3847/1538-4357/addfcf","url":null,"abstract":"Totally eclipsing contact binaries provide a unique opportunity to accurately determine mass ratios through photometric methods alone, eliminating the need for spectroscopic data. Studying low mass ratio (LMR) contact binaries is crucial for advancing our understanding of binary star evolution and the formation of rare optical transients known as red novae. We identified 143 totally eclipsing contact binaries from the Transiting Exoplanet Survey Satellite. These high-precision light curves reveal a distinct O’Connell effect, which we interpret by introducing a cool spot on the primary star. Training a neural network model that includes cool spot parameters can generate a high-precision light curve 2 orders of magnitude faster than Phoebe. Utilizing the neural network (NNnol3) model combined with the Markov Chain Monte Carlo algorithm, we rapidly derived the fundamental parameters of these systems. By leveraging the relationship between orbital period and semimajor axis using the Random Sample Consensus algorithm, we estimated their absolute parameters. Our analysis identified 96 targets with mass ratios below 0.25, all of which were not listed in any previous catalog, thus signifying the discovery of new LMR system candidates. Assuming all 143 binary systems are affected by a third light during parameter estimation, we train a neural network (NNl3) model considering the third light. Then we calculate the residuals between the mass ratio ql3 (considering the third light) and qnol3 (neglecting it). For these residuals, the 25th percentile (Q1) is 0.012, the median (Q2) is 0.026, and the 75th percentile (Q3) is 0.05.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144630155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Prestellar Cores in Turbulent Clouds: Properties of Critical Cores 湍流云中的恒星前核：临界核的性质

The Astrophysical Journal Pub Date : 2025-07-14 DOI: 10.3847/1538-4357/ade239

Sanghyuk Moon and Eve C. Ostriker

{"title":"Prestellar Cores in Turbulent Clouds: Properties of Critical Cores","authors":"Sanghyuk Moon and Eve C. Ostriker","doi":"10.3847/1538-4357/ade239","DOIUrl":"https://doi.org/10.3847/1538-4357/ade239","url":null,"abstract":"A fraction of the dense cores within a turbulent molecular cloud will eventually collapse to form stars. Identifying the physical criteria for instability and analyzing critical core properties is therefore necessary to star formation theory. Here we quantify the characteristics of an ensemble of “critical cores” on the verge of collapse. This critical epoch was identified in a companion paper, which followed the dynamical evolution of prestellar cores in numerical simulations of turbulent, self-gravitating clouds. We find that radial profiles of density and turbulent velocity dispersion in individual critical cores are consistent with our new model for turbulent equilibrium spheres. While a global linewidth–size relation exists for a cloud with given size and Mach number, the turbulent scaling relations around each core exhibit significant variations. As a result, there is no single density threshold for collapse; instead, cores collapse at a range of densities determined by the local sonic scale and gravitational potential environment. The critical cores in our simulations are mostly transonic; we do not find either purely thermal or highly turbulent cores. In our low Mach number model, which better resolves the characteristic mass and sonic scales, we find marginal evidence that the core mass function (CMF) of critical cores peaks around a characteristic mass scale associated with the large-scale cloud properties. We highlight the importance of constructing the CMF at the critical time for the purpose of testing gravoturbulent fragmentation theories, and derive the resolution requirements to unambiguously identify the peak of the CMF.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144630336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Penetrative Convection in Rotating Tilted f-plane with Multiple Radiative and Convective Layers 多辐射层和对流层旋转倾斜f面中的穿透对流

The Astrophysical Journal Pub Date : 2025-07-14 DOI: 10.3847/1538-4357/ade2d6

Sethulakshmy Edathara Sreenivasan and Tao Cai

{"title":"Penetrative Convection in Rotating Tilted f-plane with Multiple Radiative and Convective Layers","authors":"Sethulakshmy Edathara Sreenivasan and Tao Cai","doi":"10.3847/1538-4357/ade2d6","DOIUrl":"https://doi.org/10.3847/1538-4357/ade2d6","url":null,"abstract":"In this paper, we conducted a linear instability analysis to investigate penetrative convection in rotating, tilted f-planes with multiple convectively stable and unstable layers. Our findings indicate that penetrative distance decreases with increasing rotational and stratification strengths. We also observed that teleconvection, multiroll convection, and cutoff convection, previously identified in two-layer models, are present in multilayer models. For a three-layer model, the flow exhibits an up-down symmetric pattern for penetrative convection at the poles. However, this symmetry is disrupted in tilted f-planes when the flow drifts in equatorward or poleward directions. At mid- to low latitudes, poleward flow tends to enhance penetration in the upper layers, while equatorward flow facilitates penetration in the lower layers. The disruption of up-down symmetry is also observed in multilayer models with more layers when oscillatory convection occurs. Our findings suggest that upward and downward penetration could be significantly different in stars or planets with multilayer structures. However, under a strong stable composition gradient, the instability is found to be reduced.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144630340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

FUOr-Aur 0544+3330: A New Young Stellar Object Outburst in the Outskirts of Auriga OB1, Viewed Face-on FUOr-Aur 0544+3330：在御夫座OB1外围的一个新的年轻恒星爆发，正面观察

The Astrophysical Journal Pub Date : 2025-07-14 DOI: 10.3847/1538-4357/ade14d

Lynne A. Hillenbrand, Adolfo S. Carvalho, Dan Stern, Michael Connelley, Facundo Pérez Paolino, Ahaan Shetty, Zachariah Milby and Howard Isaacson

{"title":"FUOr-Aur 0544+3330: A New Young Stellar Object Outburst in the Outskirts of Auriga OB1, Viewed Face-on","authors":"Lynne A. Hillenbrand, Adolfo S. Carvalho, Dan Stern, Michael Connelley, Facundo Pérez Paolino, Ahaan Shetty, Zachariah Milby and Howard Isaacson","doi":"10.3847/1538-4357/ade14d","DOIUrl":"https://doi.org/10.3847/1538-4357/ade14d","url":null,"abstract":"We present a newly appreciated FU Ori outburst event that began in 2019 and reached a peak in early 2021. Suspected young stellar object WISE J054452.25+333009.6 experienced substantial brightening, in excess of −5 mag at optical wavelengths and −2.5 mag at mid-infrared wavelengths. The time from near-quiescence to peak brightness was approximately 24 months. Optical and near-infrared spectra confirm that the outbursting source (hereby designated FUOr-Aur 0544+3330) shows all the hallmarks of the FU Ori class, including the Li i indicator of stellar youth. The mix of ionized and neutral atomic lines, alongside prominent molecular absorption features, is consistent with the expected change in spectral type from earlier in the optical to later types in the near-infrared. The closest analog among well-studied FU Ori objects is V1515 Cyg. Both sources have unusually narrow-lined absorption spectra that can be explained by a face-on disk orientation, such that disk-broadening is minimized and wind-induced blueshift (in e.g., Hα, NaD, Ca ii) is maximized. Both the optical through infrared spectral energy distribution and high-resolution spectrum are well-fit by a pure-accretion disk model. Adopting a distance of d = 1.5 kpc, the accretion and central star parameters are M⊙ yr−1, M* = 0.17 M⊙, and Rinner = 1.04 R⊙. Other fitted values are disk inclination i = 5.9 deg and source extinction AV = 1.83 mag. These parameters yield accretion luminosity Lacc = 8.4 L⊙ and maximum disk temperature K.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144640075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Response of the LMC’s Bar to a Recent SMC Collision and Implications for the SMC’s Dark Matter Profile 大麦哲伦星系棒子对最近一次麦哲伦星系碰撞的响应及其对麦哲伦星系暗物质剖面的启示

The Astrophysical Journal Pub Date : 2025-07-14 DOI: 10.3847/1538-4357/ade0ae

Himansh Rathore, Gurtina Besla, Kathryne J. Daniel and Leandro Beraldo e Silva

{"title":"Response of the LMC’s Bar to a Recent SMC Collision and Implications for the SMC’s Dark Matter Profile","authors":"Himansh Rathore, Gurtina Besla, Kathryne J. Daniel and Leandro Beraldo e Silva","doi":"10.3847/1538-4357/ade0ae","DOIUrl":"https://doi.org/10.3847/1538-4357/ade0ae","url":null,"abstract":"The LMC’s stellar bar is offset from the outer disk center, tilted from the disk plane, and does not drive gas inflows. These properties are atypical of bars in gas-rich galaxies, yet the LMC bar’s strength and radius are similar to typical barred galaxies. Using N-body hydrodynamic simulations, we show that the LMC’s unusual bar is explainable if there was a recent collision (impact parameter ≈2 kpc) between the LMC and SMC. Pre-collision, the simulated bar is centered and coplanar. Post-collision, the simulated bar is offset (≈1.5 kpc) and tilted (≈8 6). The simulated bar offset reduces with time, and comparing with the observed offset (≈0.8 kpc) suggests the timing of the true collision to be 150–200 Myr ago. Then, 150 Myr post-collision, the LMC’s bar is centered with its dark matter (DM) halo, whereas the outer disk center is separated from the DM center by ≈1 kpc. The SMC collision produces a tilted-ring structure for the simulated LMC, consistent with observations. Post-collision, the simulated LMC bar’s pattern speed decreases by a factor of 2. We also provide a generalizable framework to quantitatively compare the LMC’s central gas distribution in different LMC–SMC interaction scenarios. We demonstrate that the SMC’s torques on the LMC’s bar during the collision are sufficient to explain the observed bar tilt, provided the SMC’s total mass within 2 kpc was (0.8–2.4) × 109M⊙. Therefore, the LMC bar’s tilt constrains the SMC’s pre-collision DM profile, and requires the SMC to be a DM-dominated galaxy.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144630330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Crucial Role of Third Body in Formation and Evolution of Contact Binary Systems: Evidence from CY Ari and IK Lyn 第三体在接触双星系统形成和演化中的关键作用：来自CY Ari和IK Lyn的证据

The Astrophysical Journal Pub Date : 2025-07-14 DOI: 10.3847/1538-4357/ade152

Hu-Shan Xu, Zhong-Tao Han, Wei-wei Na, Zhi-Hua Wang, Wen-wu Ma and Li-Ying Zhu

{"title":"The Crucial Role of Third Body in Formation and Evolution of Contact Binary Systems: Evidence from CY Ari and IK Lyn","authors":"Hu-Shan Xu, Zhong-Tao Han, Wei-wei Na, Zhi-Hua Wang, Wen-wu Ma and Li-Ying Zhu","doi":"10.3847/1538-4357/ade152","DOIUrl":"https://doi.org/10.3847/1538-4357/ade152","url":null,"abstract":"CY Ari and IK Lyn are two eclipsing binary systems that share the same spectral type but exhibit significantly different metallicities. Based on the Wilson–Devinney (W-D) method, the first photometric solutions are obtained by analyzing the new complete BVRcIc light curves. The completely eclipsing nature of the light curves allows for the determination of reliable photometric parameters for both systems. Analysis of the light curves indicates that the two systems are structurally similar. Both belong to W-type shallow contact binary systems, with nearly identical degrees of contact. The O − C analysis demonstrates that the orbital periods of CY Ari and IK Lyn are increasing over the long term, with the increase rate for IK Lyn being significantly higher than that for CY Ari. This discrepancy may arise from different mass transfer rates from the secondary star to the primary star. Additionally, a periodic oscillation with a period of 5.4 yr has been detected in CY Ari, potentially attributable to the light-time effect of an unseen third body. An analysis of the age and evolutionary stage elucidates the reasons behind the divergent evolutionary paths of CY Ari and IK Lyn. The presence of the third body accelerates the evolution of CY Ari by removing angular momentum from the central binary pair. Although CY Ari was formed later than IK Lyn, it has evolved into a similar stage. This study provides critical evidence of the significant role played by a third body in the formation and evolution of contact binary systems.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144630338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0