Astrophysics and Space Science最新文献

{"title":"Icarus’s perihelion advance explored through Newtonian and relativistic gravity, and the Vulcan hypothesis","authors":"S. P. Pogossian","doi":"10.1007/s10509-026-04570-8","DOIUrl":"10.1007/s10509-026-04570-8","url":null,"abstract":"<div><p>In this work, a comparative study of the perihelion precession of the inner planets is presented, considering both general relativity and Newtonian gravity extended to include a hypothetical planet, Vulcan, modeled as a planetary-mass primordial black hole located between Mercury and Venus. Two computational approaches are examined: the conventional method based on the secular evolution rate of the perihelion longitude and an alternative approach based on the rotation of the Laplace–Runge–Lenz vector. A Vulcan with a semi-major axis of 0.545 astronomical units and a mass approximately one-third that of Mercury reproduces the observed perihelion advances of Mercury, Earth, and Mars. However, it predicts a perihelion advance for the asteroid Icarus significantly larger than the relativistic value. As a planetary mass primordial black hole, Vulcan would be electromagnetically invisible, and its presence could only be inferred through gravitational perturbations. For Mercury, Earth, and Mars, the perihelion advances computed using both methods are mutually consistent within the Newtonian-plus-Vulcan framework and in general relativity. The analysis of Venus’s perihelion advance reveals large fluctuations, and it is therefore excluded from the study. For asteroid Icarus, the two methods yield divergent results: only the Laplace–Runge–Lenz vector approach produces values consistent with general relativity. These results demonstrate that the Laplace–Runge–Lenz vector method provides a reproducible and intuitive framework for calculating perihelion advance, capturing the effect as a rotation of a vector that directly points to the perihelion position, offering a straightforward and physically intuitive alternative to the traditional perihelion-longitude approach. The orbital motion of Icarus provides a particularly sensitive test for distinguishing between classical Newtonian dynamics extended to include a hypothetical Vulcan and relativistic predictions. A deeper understanding of the orbital dynamics of solar system bodies enables refinement of gravitational models in the inner solar system and more accurate predictions for near-Earth object trajectories.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147643172","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":"Whistler-mode waves with latitudinal variation drive by loss-cone beams and a parallel DC electric field in Jupiter’s magnetosphere","authors":"Ankita,&nbsp;R. S. Pandey,&nbsp;R. K. Tyagi,&nbsp;A. K. Dhaikar","doi":"10.1007/s10509-026-04569-1","DOIUrl":"10.1007/s10509-026-04569-1","url":null,"abstract":"<div><p>We derive the dispersion relation and growth rates of parallel-propagating whistler-mode waves in a collisionless Jovian plasma containing relativistic hot electron and ion beams and a parallel DC electric field. Using a generalized loss-cone distribution, we obtain analytical expressions for the real frequency and dimensionless growth rate as functions of temperature anisotropy, relativistic factor, beam density and DC field strength, and compute results for conditions representative of Jupiter at L ≈ 17 R_J. Compared to earlier studies, our analysis on Jupiter’s magnetosphere (1) incorporates a generalized unperturbed distribution with an explicit loss-cone index, building on but extending prior formulations by integrating these elements self-consistently for Jovian conditions (2) quantifies the combined influence of a parallel DC electric field and relativistic beam effects on growth rates for both electron and ion beams, and (3) presents latitudinal variations using an empirical magnetic field model Jupiter’s magnetosphere. Our results demonstrate that temperature anisotropy and magnetic latitude strongly modulate whistler growth, while relativistic factor and hot electron and ion beam density suppress it — implications that can be tested against Juno wave and particle data.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147643096","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":"Study of Doppler velocity and half-width variations in solar H(alpha ) spicules and prominences","authors":"M. Sikharulidze,&nbsp;D. Khutsishvili,&nbsp;E. Khutsishvili,&nbsp;V. Kakhiani,&nbsp;T. Tsinamdzgvrishvili","doi":"10.1007/s10509-026-04567-3","DOIUrl":"10.1007/s10509-026-04567-3","url":null,"abstract":"<div><p>Special attention should be paid to oscillations detected in the upper solar atmosphere, as they may reflect the transport of energy into the corona by magnetohydrodynamic (MHD) waves. The aim of this study is to investigate the non-stationary physical processes taking place in solar spicules and prominences, as well as the relationship between them. The study and comparison of spicules and prominences, and the obtained results, will introduce certain new insights for explaining the physical processes occurring within them. At the Abastumani Astrophysical Observatory, spectrograms in the hydrogen H<span>(alpha )</span> line were obtained at two different heights (7500 km and 8000 km) with the aid of a large, non-eclipse coronagraph. The standard errors in the determination of Doppler velocities and FWHM are ±0.35 km/s and 0.04 Å, respectively. The lifetimes of almost all measured spicules were about 20 minutes, thus resembling type I spicules. Future observational and theoretical studies will contribute to a better understanding of the nature of phenomena occurring in the solar atmosphere and to clarifying possible links between them. From the processing and analysis of the observational material, the following results were obtained: (1) For H<span>(alpha)</span> prominences, no asymmetry was found in the temporal variations of Doppler velocities and half-widths. (2) In H<span>(alpha)</span> spicules and prominences, the time variation of Doppler velocities proceeds in approximately the same manner. (3) An asymmetry in the temporal variation of half-widths was detected in H<span>(alpha )</span> spicules and prominences. (4) In Sect. 1, a brief overview of the study of spicules and prominences is presented. (5) In Sect. 2, the observations and data processing are described. (6) In Sect. 3, the analysis of observational data, including Doppler velocities and FWHM, is discussed. (7) In Sect. 4, the discussion and conclusions are presented.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147642654","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":"Where are Gaia’s small black holes?","authors":"Maya Fishbach,&nbsp;Katelyn Breivik,&nbsp;Reinhold Willcox,&nbsp;L. A. C. van Son","doi":"10.1007/s10509-026-04554-8","DOIUrl":"10.1007/s10509-026-04554-8","url":null,"abstract":"<div><p><i>Gaia</i> has recently revealed a population of over 20 compact objects in wide astrometric binaries, while LIGO-Virgo-KAGRA (LVK) have observed around 100 compact object binaries as gravitational-wave (GW) mergers. Despite belonging to different systems, the compact objects discovered by both <i>Gaia</i> and the LVK follow a multimodal mass distribution, with a global maximum at neutron star (NS) masses (<span>(sim 1)</span>–<span>(2,M_{odot })</span>) and a secondary local maximum at black hole (BH) masses <span>(sim 10,M_{odot })</span>. However, the relative dearth of objects, or “mass gap,” between these modes is more pronounced among the wide binaries observed by <i>Gaia</i> compared to the GW population, with <span>(9^{+10}_{-6}%)</span> of GW component masses falling between 2.5–<span>(5,M_{odot })</span> compared to <span>(lesssim 5%)</span> of <i>Gaia</i> compact objects. We explore whether this discrepancy can be explained by the natal kicks received by low-mass BHs. GW progenitor binaries may be more likely to survive natal kicks, because the newborn BH has a more massive companion and/or is in a tighter binary than <i>Gaia</i> progenitor binaries. We compare the survival probabilities of <i>Gaia</i> and GW progenitor binaries as a function of natal kick strength and pre-supernova binary parameters, and map out the parameter space and kick strength required to disrupt the progenitor binaries leading to low-mass BHs in <i>Gaia</i> systems more frequently than those in GW systems.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147606790","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 multi-parametric comparative study of Solar Cycles 23, 24, and 25 using solar and interplanetary disturbance indices","authors":"Munendra Singh,&nbsp;Y. P. Singh","doi":"10.1007/s10509-026-04561-9","DOIUrl":"10.1007/s10509-026-04561-9","url":null,"abstract":"<div><p>This study presents a comprehensive multi-parametric comparison of solar and interplanetary disturbances during Solar Cycles 23, 24, and 25. Using key indices including sunspot number (SSN), solar radio flux (F10.7), Coronal Mass Ejections (CMEs), High-Speed Streams (HSSs), Co-rotating Interaction Regions (CIRs), interplanetary (IP) shocks, Sudden Storm Commencements (SSCs), and Forbush Decreases (FDs), the temporal evolution and relative strengths of the three cycles are examined. The results show that Solar Cycle 23 was the strongest, exhibiting pronounced magnetic activity and frequent eruptive events. Solar Cycle 24 was significantly weaker across all parameters, reflecting reduced solar dynamo efficiency and diminished levels of heliospheric disturbances. Preliminary observations of the rising phase of Solar Cycle 25 indicate a moderate recovery, with activity levels exceeding those of Cycle 24 but remaining below those of Cycle 23. The combined comparison highlights a progression from strong to weak to moderate in solar behaviour, providing critical insights into long-term solar variability, heliospheric modulation, and space weather forecasting for upcoming solar activity phases.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147561569","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":"Retraction Note: An optimized analytical-numerical method for Kepler’s equation with near-machine precision and high computational speedup","authors":"Charbel Mamlankou,&nbsp;Bernard Sognombo","doi":"10.1007/s10509-026-04568-2","DOIUrl":"10.1007/s10509-026-04568-2","url":null,"abstract":"","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147560879","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 importance of laboratory experiments for interpreting exoplanet observations","authors":"Maggie A. Thompson","doi":"10.1007/s10509-026-04564-6","DOIUrl":"10.1007/s10509-026-04564-6","url":null,"abstract":"<div><p>With the advanced capabilities of ground- and space-based telescopes, exoplanet science is beginning to characterize the physics and chemistry of exoplanet atmospheres. However, interpreting exoplanet observations requires sophisticated modeling tools that rely on laboratory data to provide critical inputs and constraints. In preparation for the influx of observational data that the coming decades will bring, laboratory experiments that simulate the diverse conditions expected in exoplanet atmospheres, surfaces and interiors are vital to advancing models and thereby our understanding of these worlds. Here we discuss the key areas where laboratory experiments are providing fundamental data for exoplanet models, particularly for low-mass planets from rocky worlds to sub-Neptunes. First, we present a series of experiments to measure outgassing and volatile solubilities that are essential for establishing the connection between low-mass exoplanet interiors and their observable atmospheres. We then discuss additional laboratory techniques that can be used to understand the interior-atmosphere connection and simulate the high pressure-high temperature conditions of exoplanet interiors. Next, we summarize the experimental methods used to constrain the spectroscopic properties of atmospheric gases and aerosols along with their formation and reaction mechanisms. We also discuss how similar methods can be used to constrain exoplanet surface compositions, which is important for interpreting observations of atmosphere-less worlds. Finally, we conclude by presenting several examples of astrobiology experiments that constrain how life can modify the atmosphere and surface of rocky exoplanets. Together, these laboratory efforts are crucial to maximizing the scientific yield of exoplanet observations in the coming decades.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10509-026-04564-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147560878","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":"Material-dependent temperature modelling of lunar impact flashes: validation with NELIOTA observations","authors":"N. Rakesh Chandra","doi":"10.1007/s10509-026-04565-5","DOIUrl":"10.1007/s10509-026-04565-5","url":null,"abstract":"<div><p>This study adapts the three-equation model proposed by Stober and Jacobi (Reports of the Institute of Meteorology, University of Leipzig, vol. 42, pp. 155–168, 2008) to simulate lunar atmospheric conditions and estimate the temperatures of Lunar Impact Flashes (LIFs) generated by different classes of meteoroids. The methodology is applied to 55 LIFs documented by Avdellidou and Vaubaillon (Mon. Not. R. Astron. Soc. 484(4):5212–5222, 2019), and the derived temperatures are found to be in strong agreement with the NELIOTA observational measurements. Recognizing the wide variability in meteoroid material properties—such as mechanical strength, porosity, and thermal conductivity—a three-regime modelling framework was developed, categorizing meteoroids as porous, stony, or iron-rich. Each regime addresses unique physical processes: rapid fragmentation in porous bodies, energy partitioning in stony meteoroids, and conduction-dominated behaviour in iron meteoroids. This differentiated approach effectively corrects the systematic errors introduced by traditional unified models. Validation against experimental data confirms the model’s improved predictive capability across all meteoroid types. By incorporating material-specific physics, this framework significantly enhances the accuracy of temperature estimations and offers a more reliable interpretation of lunar impact thermal phenomena. The explicit separation of material classes resolves long-standing discrepancies in peak temperature predictions, particularly for fragile cometary bodies and dense iron impactors.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147561000","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":"Deep learning method for the classification of the quality of Halpha full disk images","authors":"Xu Xiong,&nbsp;Xiao Yang,&nbsp;Xianyong Bai,&nbsp;Bo Liang,&nbsp;Song Feng","doi":"10.1007/s10509-026-04566-4","DOIUrl":"10.1007/s10509-026-04566-4","url":null,"abstract":"<div><p>Ground-based observation is important for solar physics research. However, cloud cover between the Sun and the Earth contaminates and degrades the quality of the acquired solar observation images obtained, thereby affecting the research on solar physics. Therefore, these images need to be screened and categorized. Previously, traditional methods and manual screening were capable of handling this task. However, with the advancement of technology, the observation equipment is now capable of collecting data of terabyte scale. The existing methods are unable to handle the data obtained by the observation equipment efficiently, and thus are no longer applicable. We adopted an improved deep learning method based on U-Net, integrating attention mechanisms, convolutional neural networks and feature fusion mechanisms to solve the problem of cloud coverage assessment in full-disk solar images. We utilized a dataset comprising 4350 pieces of data captured by the Solar Full-disk Multi-layer Magnetograph (SFMM), selecting precision, recall, F1 score, and macro F1 score as evaluation metrics, and evaluated the performance of our model along with the comparative experimental models through five-fold cross-validation. The Macro-Precision of our model reaches 0.9782, the score of our model on Macro-F1 is 0.9782. These metric values demonstrate that our method achieves more accurate classification of ground-based observation data.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147560630","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":"Lasting biosignatures for 165 million years in lichens detected by multiple spectroscopies and the implication for extreme environmental and exoplanetary life exploring","authors":"Guobin Jin,&nbsp;Wang Liu,&nbsp;Zhongchen Wu,&nbsp;Qiuxia Yang,&nbsp;Weilai Lu,&nbsp;Yu V. Fu,&nbsp;Yongjie Wang,&nbsp;Dong Ren,&nbsp;Wei Lin,&nbsp;Xiaohui Fu,&nbsp;Xinli Wei","doi":"10.1007/s10509-026-04558-4","DOIUrl":"10.1007/s10509-026-04558-4","url":null,"abstract":"<div><p>A type of specialized fungi, lichens, are the pioneer and predominant life form in harsh land environments on Earth with strong tolerance to extreme environment, including both extant and fossilized materials. Multiple spectroscopic techniques have been widely used in extreme-environment and planetary detection and life detection. Herein, multiple spectral methods and Energy Dispersive Spectrometer (EDS) analysis were applied to test whether lichens could be the potential biomarkers and might contain the detectable biosignatures as life signal in extreme environments and on exoplanets (such as Mars). Our results indicated that Infrared spectroscopy (IR) and EDS techniques are effective for micro-region analysis of fossil components, which could distinguish fossil and rock substrates by characteristic spectral bands and elemental component contents. More importantly, C–O stretching in phenyl and C–H stretching were detected in both extant and the 165-million-year fossil lichens by IR, which are the basic skeleton constituting the characteristic lichen secondary metabolites. Raman spectroscopy successfully identified characteristic peaks corresponding to chlorophyll and carotenoids in extant lichen samples, but strong fluorescence interference hindered its application to fossil samples. Similarly, Laser-induced breakdown spectroscopy (LIBS) analysis detected emission peaks of CN and C₂ in extant lichen samples but failed to detect these organic components in fossil samples, likely due to the loss of organic materials during fossilization. Despite limitations, integrating multiple spectral techniques is crucial for comprehensive exoplanet and extreme environment life detection missions. This study suggested that lichen can be utilized as a potential biomarker for searching the Martian and extreme environmental life, as its characteristic aromatic compounds will be the practical biosignatures lasting 165 million years. Furthermore, our study emphasizes the potential of infrared spectroscopy, among other techniques, for <i>in-situ</i> biosignature detection in extreme environment and on exoplanets (such as Mars), offering valuable insights for future exploration.</p></div>","PeriodicalId":8644,"journal":{"name":"Astrophysics and Space Science","volume":"371 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147441347","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}