Nature Astronomy最新文献

Observations of fine coronal structures with high-order solar adaptive optics 用高阶太阳自适应光学观测精细日冕结构

IF 14.1 1区物理与天体物理

Nature Astronomy Pub Date : 2025-05-27 DOI: 10.1038/s41550-025-02564-0

Dirk Schmidt, Thomas A. Schad, Vasyl Yurchyshyn, Nicolas Gorceix, Thomas R. Rimmele, Philip R. Goode

{"title":"Observations of fine coronal structures with high-order solar adaptive optics","authors":"Dirk Schmidt, Thomas A. Schad, Vasyl Yurchyshyn, Nicolas Gorceix, Thomas R. Rimmele, Philip R. Goode","doi":"10.1038/s41550-025-02564-0","DOIUrl":"https://doi.org/10.1038/s41550-025-02564-0","url":null,"abstract":"Resolving fine structures in the Sun’s corona may provide key insights into rapid eruptions and the heating of the corona. Adaptive optics systems have been used for over two decades to reach the diffraction limit of large telescopes, thereby compensating for atmospheric image blur. Current systems, however, are still limited to observations of the solar disk and fail with coronal objects, leaving fundamental coronal dynamics hidden in that blur. Here we present observations with coronal adaptive optics reaching the diffraction limit of a 1.6-m telescope to reveal very fine coronal details. Furthermore, we discovered a short-lived, fast-moving, finely twisted feature occurring during the decay phase of a flare that quickly destabilized. Coronal adaptive optics increased the spatial resolution by an order of magnitude at visible wavelengths. We report here a large portion of off-limb coronal rain material with observed scales below 100 km. This new adaptive optics scheme opens opportunities for observational discoveries at small scales beyond the solar limb in the highly dynamic corona by exploiting the diffraction limit of large ground-based telescopes.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"10 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144145893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Very-wide-orbit planets from dynamical instabilities during the stellar birth cluster phase 非常宽的轨道行星从动态不稳定在恒星诞生星团阶段

IF 14.1 1区物理与天体物理

Nature Astronomy Pub Date : 2025-05-27 DOI: 10.1038/s41550-025-02556-0

André Izidoro, Sean N. Raymond, Nathan A. Kaib, Alessandro Morbidelli, Andrea Isella

{"title":"Very-wide-orbit planets from dynamical instabilities during the stellar birth cluster phase","authors":"André Izidoro, Sean N. Raymond, Nathan A. Kaib, Alessandro Morbidelli, Andrea Isella","doi":"10.1038/s41550-025-02556-0","DOIUrl":"https://doi.org/10.1038/s41550-025-02556-0","url":null,"abstract":"Gas-giant planets have been detected on eccentric orbits several hundreds of astronomical units in size around other stars. It has been proposed that even the Sun hosts a wide-orbit planet of 5–10 Earth masses, often called Planet Nine, which influences the dynamics of distant trans-Neptunian objects. However, the formation mechanism of such planets remains uncertain. Here we use numerical simulations to show that very-wide-orbit planets are a natural by-product of dynamical instabilities that occur in planetary systems while their host stars are still embedded in natal stellar clusters. A planet is first brought to an eccentric orbit with an apoastron of several hundred astronomical units by repeated gravitational scattering by other planets, then perturbations from nearby stellar flybys stabilize the orbit by decoupling the planet from the interaction with the inner system. In our Solar System, the two main events likely conducive to planetary scattering were the growth of Uranus and Neptune, and the giant planets instability. We estimate a 5–10% likelihood of creating a very-wide-orbit planet if either happened while the Sun was still in its birth cluster, increasing to 40% if both were. In our simulated exoplanetary systems, the trapping efficiency is 1–5%. Our results imply that planets on wide, eccentric orbits occur at least 10−3 per star.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"42 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144145713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Enhanced magnetic activity in rapidly rotating binary stars 在快速旋转的双星中增强的磁场活动

IF 14.1 1区物理与天体物理

Nature Astronomy Pub Date : 2025-05-23 DOI: 10.1038/s41550-025-02562-2

Jie Yu, Charlotte Gehan, Saskia Hekker, Michäel Bazot, Robert H. Cameron, Patrick Gaulme, Timothy R. Bedding, Simon J. Murphy, Zhanwen Han, Yuan-Sen Ting, Jamie Tayar, Yajie Chen, Laurent Gizon, Jason Nordhaus, Shaolan Bi

{"title":"Enhanced magnetic activity in rapidly rotating binary stars","authors":"Jie Yu, Charlotte Gehan, Saskia Hekker, Michäel Bazot, Robert H. Cameron, Patrick Gaulme, Timothy R. Bedding, Simon J. Murphy, Zhanwen Han, Yuan-Sen Ting, Jamie Tayar, Yajie Chen, Laurent Gizon, Jason Nordhaus, Shaolan Bi","doi":"10.1038/s41550-025-02562-2","DOIUrl":"https://doi.org/10.1038/s41550-025-02562-2","url":null,"abstract":"Stellar activity is fundamental to stellar evolution and the formation and habitability of exoplanets. Magnetic surface activity is driven by the interaction between convective motions and rotation in cool stars, resulting in a dynamo process. In single stars, activity increases with rotation rate until it saturates for stars with rotation periods Prot < 3–10 d. However, the mechanism responsible for saturation remains unclear. Observations indicate that red giants in binary systems that are in spin–orbit resonance exhibit stronger chromospheric activity than single stars with similar rotation rates, suggesting that tidal flows can influence surface activity. Here, we investigate the chromospheric activity of main-sequence binary stars to understand the impact of tidal forces on saturation phenomena. For binaries with 0.5 < Prot (d) < 1, mainly contact binaries that share a common thermal envelope, we find enhanced activity rather than saturation. This result supports theoretical predictions that a large-scale α–ω dynamo during common-envelope evolution can generate strong magnetic fields. We also observe supersaturation in chromospheric activity, a phenomenon tentatively noted previously in coronal activity, where activity levels fall below saturation and decrease with shorter rotation periods. Our findings emphasize the importance of studying stellar activity in stars with extreme properties compared with the Sun’s.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"131 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144123049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

A growing family of two-faced stars 一个不断壮大的双面明星家庭

IF 14.1 1区物理与天体物理

Nature Astronomy Pub Date : 2025-05-21 DOI: 10.1038/s41550-025-02570-2

Bokyoung Kim

{"title":"A growing family of two-faced stars","authors":"Bokyoung Kim","doi":"10.1038/s41550-025-02570-2","DOIUrl":"https://doi.org/10.1038/s41550-025-02570-2","url":null,"abstract":"Roughly one in five white dwarfs (WDs) within 100 pc undergo spectral transitions from one type to another. These changes are driven by internal convective processes that mix surface materials, leaving surface compositions homogeneous. However, a few very rare cases — so-called double-faced WDs — show spectral variability over just a few hours, a timescale too rapid and surface composition too inhomogeneous for homogeneous atmospheric models to explain. Adam Moss and colleagues discovered one such double-faced WD, SDSS J0847+4842, and revisited another known WD, LB 8915, confirming its double-faced nature. By investigating these two, as well as five previously known double-faced WDs, the authors propose that magnetism drives the observed frequent spectral-type changes.Through a time-series spectroscopic survey of six unresolved WD binary candidates, the authors found that one of them (SDSS J0847+4842) is not a binary but a massive single WD showing spectroscopic variations over 6.5 or 8.9 hours. They also revisited LB 8915 — a known DBA-type WD — whose time-series spectra show hydrogen-line variability every 5.7 hours, while helium lines remain consistently strong. The time-resolved spectra of both objects are well explained by a model with hydrogen polar caps and a helium equatorial belt. These discoveries increase the number of known double-faced WDs to seven.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"57 1","pages":"623-623"},"PeriodicalIF":14.1,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144114016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Increased hydrogen escape from Mars atmosphere during periods of high obliquity 在高倾角期间，火星大气中氢气的逃逸增加

IF 14.1 1区物理与天体物理

Nature Astronomy Pub Date : 2025-05-21 DOI: 10.1038/s41550-025-02561-3

Gabriella Gilli, Francisco González-Galindo, Jean-Yves Chaufray, Ehouarn Millour, François Forget, Franck Montmessin, Franck Lefèvre, Joseph Naar, Yangcheng Luo, Margaux Vals, Loïc Rossi, Miguel Ángel López-Valverde, Adrián Brines

引用次数: 0

Slow-moving magnetar a new breed? 移动缓慢的磁星是一个新品种？

IF 14.1 1区物理与天体物理

Nature Astronomy Pub Date : 2025-05-21 DOI: 10.1038/s41550-025-02567-x

Paul Woods

{"title":"Slow-moving magnetar a new breed?","authors":"Paul Woods","doi":"10.1038/s41550-025-02567-x","DOIUrl":"https://doi.org/10.1038/s41550-025-02567-x","url":null,"abstract":"Magnetars are observationally rare, highly magnetic neutron stars, potentially arising from core-collapse supernovae. However, other origins have been suggested: stellar mergers or an induced collapse within a progenitor binary system. Determining the formation mechanism of magnetars is an ongoing pursuit, one that is often complicated by dense natal environments. Ashley Chrimes and colleagues have measured the proper motion of Galactic magnetar SGR 0501+4516, finding that its velocity is too low to have been created in a standard core-collapse supernova.SGR 0501+4516 was discovered in 2008, and its relatively low extinction and low crowding allowed the detection and monitoring of a near-infrared counterpart for 12 subsequent years, with HST and ground-based telescopes. The tangential velocity of the magnetar was determined to be 51 ± 14 km s−1, comparable to the slowest ~10% of pulsars. Such a low velocity, along with the direction of motion, rules out an origin within the nearby supernova remnant HB9. There also do not appear to be any nearby young star-forming regions or clusters in the direction opposite to that of the magnetar’s travel, even if SGR 0501+4516 were an order of magnitude older than it appears to be. This lack also disfavours SGR 0501+4516’s origin in a supernova with a low ejecta mass (for instance, that produced by a stripped star), in which case the remnant would be undetectable.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"44 1","pages":"620-620"},"PeriodicalIF":14.1,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144114012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Exploring the Universe before the Big Bang 探索大爆炸前的宇宙

IF 14.1 1区物理与天体物理

Nature Astronomy Pub Date : 2025-05-21 DOI: 10.1038/s41550-025-02553-3

Francesca Vidotto

引用次数: 0

Real-time changes from Europa's surface 木卫二表面的实时变化

IF 14.1 1区物理与天体物理

Nature Astronomy Pub Date : 2025-05-21 DOI: 10.1038/s41550-025-02568-w

Luca Maltagliati

引用次数: 0

Concerning the possible exomoons around Kepler-1625 b and Kepler-1708 b 关于开普勒-1625 b和开普勒-1708 b周围可能存在的系外卫星

IF 14.1 1区物理与天体物理

Nature Astronomy Pub Date : 2025-05-21 DOI: 10.1038/s41550-025-02547-1

David Kipping, Alex Teachey, Daniel A. Yahalomi, Ben Cassese, Billy Quarles, Steve Bryson, Brad Hansen, Judit Szulágyi, Chris Burke, Kevin Hardegree-Ullman

{"title":"Concerning the possible exomoons around Kepler-1625 b and Kepler-1708 b","authors":"David Kipping, Alex Teachey, Daniel A. Yahalomi, Ben Cassese, Billy Quarles, Steve Bryson, Brad Hansen, Judit Szulágyi, Chris Burke, Kevin Hardegree-Ullman","doi":"10.1038/s41550-025-02547-1","DOIUrl":"https://doi.org/10.1038/s41550-025-02547-1","url":null,"abstract":"arising from Heller, R. & Hippke, M. Nature Astronomy https://doi.org/10.1038/s41550-023-02148-w (2024)Recently, Heller and Hippke1 argued that the exomoon candidates Kepler-1625 b-i and Kepler-1708 b-i were allegedly ‘refuted’. In this Matters Arising, we address these claims. For Kepler-1625 b-i, we show that their Hubble light curve is identical to that previously published by the same lead author2, in which the moon-like dip was recovered. Indeed, our fits of their data again recover this dip with improved residuals compared with the work of Heller and Hippke1. Their fits therefore somehow missed this deeper likelihood maximum, producing apparently unconverged posteriors. Consequently, their best-fitting moon is the same radius as the planet, Kepler-1625 b-i, a radically different signal from that originally claimed3. The authors then inject this solution into the Kepler data and remark, as a point of concern, how retrievals obtain much higher significances than originally reported. However, this stems from the injection of a fundamentally different signal. We demonstrate that their Hubble light curve exhibits ~20% higher noise and discards 11% of the useful data, which compromises its ability to recover the subtle signal of Kepler-1625 b-i.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"42 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144104727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Surprisingly faint first galaxies 令人惊讶的微弱第一星系

IF 14.1 1区物理与天体物理

Nature Astronomy Pub Date : 2025-05-21 DOI: 10.1038/s41550-025-02569-9

Lindsay Oldham

{"title":"Surprisingly faint first galaxies","authors":"Lindsay Oldham","doi":"10.1038/s41550-025-02569-9","DOIUrl":"https://doi.org/10.1038/s41550-025-02569-9","url":null,"abstract":"A puzzling feature of cosmic dawn is that bright galaxies in the redshift range 10 < z < 15 are overabundant relative to HST-based expectations but have so far evaded detection at higher redshifts, despite JWST’s technical capacity to do so. Vasily Kokorev and colleagues take advantage of the lensing magnification of the galaxy cluster Abell S1063 and the ultra-deep NIRCam survey GLIMPSE to identify two robust candidates at z > 16.Combining a Lyman-alpha dropout search with photometric redshift estimates to rule out star-bursting interlopers, the authors narrow down an initial catalogue of lensed background sources to these two final objects, with putative redshifts in the range z ~ 15.8−16.4. Though their ~200 pc effective radii and low dust content are consistent with expectations for very newly formed galaxies, photometric modelling indicates low star formation rate surface densities relative to extrapolations from lower redshifts. Equally surprising is that the volume searched behind the cluster implies a significantly higher number density than expected based on upper limits from previous JWST surveys, in which no strong candidates have yet been found at these redshifts.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"19 1","pages":"622-622"},"PeriodicalIF":14.1,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144114011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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