Nature Astronomy最新文献

{"title":"Black in cosmology","authors":"John. C. Hood, Marcell Howard, Elizabeth Meador","doi":"10.1038/s41550-025-02577-9","DOIUrl":"https://doi.org/10.1038/s41550-025-02577-9","url":null,"abstract":"As part of Black Space Week 2025, two cosmologists and an astroparticle physicist share information about their scientific interests, research projects and personal motivations for working in astronomy.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"1 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329028","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}

{"title":"A gas-rich cosmic web revealed by the partitioning of the missing baryons","authors":"Liam Connor, Vikram Ravi, Kritti Sharma, Stella Koch Ocker, Jakob Faber, Gregg Hallinan, Charlie Harnach, Greg Hellbourg, Rick Hobbs, David Hodge, Mark Hodges, Nikita Kosogorov, James Lamb, Casey Law, Paul Rasmussen, Myles Sherman, Jean Somalwar, Sander Weinreb, David Woody, Ralf M. Konietzka","doi":"10.1038/s41550-025-02566-y","DOIUrl":"https://doi.org/10.1038/s41550-025-02566-y","url":null,"abstract":"<p>Approximately half of the Universe’s dark matter resides in collapsed halos; significantly less than half of the baryonic matter (protons and neutrons) remains confined to halos. A small fraction of baryons are in stars and the interstellar medium within galaxies. The majority are diffuse (&lt;10⁻³ cm⁻³) and ionized (neutral fraction &lt;10⁻⁴), located in the intergalactic medium (IGM) and in the halos of galaxy clusters, groups and galaxies. This diffuse ionized gas is notoriously difficult to measure, but has wide implications for galaxy formation, astrophysical feedback and precision cosmology. Recently, the dispersion of extragalactic fast radio bursts (FRBs) has been used to measure the total content of cosmic baryons. Here we present a large cosmological sample of FRB sources localized to their host galaxies. We have robustly partitioned the missing baryons into the IGM, galaxy clusters and galaxies, providing a late-Universe measurement of the cosmic baryon abundance, <span>({varOmega }_{{mathrm{b}}}{h}_{70}=0.05{1}_{-0.006}^{+0.006})</span>, where <i>Ω</i>_b is the baryon density parameter and <i>h</i>₇₀ is the scaled Hubble constant. Our results indicate efficient feedback processes that can deplete galaxy halos and enrich the IGM (total baryon fraction in the IGM is <span>({f}_{{rm{IGM}}}=0.7{6}_{-0.11}^{+0.10})</span>), agreeing with the baryon-rich cosmic web scenario seen in cosmological simulations. Our results may reduce the ‘<i>S</i>₈ tension’ in cosmology, as strong feedback leads to suppression of the matter power spectrum.</p>","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"10 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144296141","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}

{"title":"Deep chemical weathering on ancient Mars landscapes driven by erosional and climatic patterns","authors":"Rhianna D. Moore, Timothy A. Goudge, Athanasios Klidaras, Briony H. N. Horgan, Adrian Broz, Robin Wordsworth, William H. Farrand","doi":"10.1038/s41550-025-02584-w","DOIUrl":"https://doi.org/10.1038/s41550-025-02584-w","url":null,"abstract":"<p>Across Mars exist thick clay mineral-bearing stratigraphies (CSs), thought to have formed through top-down leaching early in Mars’s geological history (&gt;3.7 billion years ago) under warmer, wetter conditions than at present. On Earth, such deposits require specific landscape and climatic conditions to develop; however, it is unclear how Mars’s local and global topographic variations and past climate activity influenced surface weathering and CS formation. Here we present observations that show that CSs tend to occur in areas where chemical weathering was favoured over physical erosion, farther from valley network activity and nearer standing bodies of water. We conclude that the development of thick CSs through enhanced chemical weathering on this tectonically inactive planet may have led to an imbalanced weathering–climate feedback compared with Earth. Our results support the hypothesis that long-term irreversible sequestration of water and cations within clay minerals may have inhibited hydrological activity, and potentially carbonate mineral formation, over time.</p>","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"13 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144296140","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}

{"title":"A massive planet with a low-mass host challenges formation theories","authors":"","doi":"10.1038/s41550-025-02560-4","DOIUrl":"https://doi.org/10.1038/s41550-025-02560-4","url":null,"abstract":"A giant exoplanet has been discovered transiting a star with a mass just 20% of that of the Sun. This exoplanetary system poses a challenge to the current understanding of how giant planets form.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"9 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144278566","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}

{"title":"Earth-mass planets with He atmospheres in the habitable zone of Sun-like stars","authors":"Helmut Lammer, Manuel Scherf, Nikolai V. Erkaev, Daria Kubyshkina, Kseniia D. Gorbunova, Luca Fossati, Peter Woitke","doi":"10.1038/s41550-025-02550-6","DOIUrl":"https://doi.org/10.1038/s41550-025-02550-6","url":null,"abstract":"<p>The discovery of many low-mass exoplanets, including several planets within the habitable zone of their host stars, has led to the question of which kind of atmosphere surrounds them. Recent exoplanet detections have revealed the existence of a large population of low-mass planets (&lt;3 <i>M</i>_{<span>⊕</span>}) with H₂-dominated atmospheres that must have been accreted from the protoplanetary disk. As the gas disk usually has an ~10% fraction of helium, we model the possible enrichment of the primordial He fraction in the atmosphere of planets with mass between 0.75 <i>M</i>_{<span>⊕</span>} and 3.0 <i>M</i>_{<span>⊕</span>} that orbit in the classical habitable zone of Sun-like stars. Depending on the mass accreted by the planet during the gas disk phase and the stellar high-energy flux between ~10 and 120 nm, we find that Earth-like planets with masses between ~0.95 <i>M</i>_{<span>⊕</span>} and 1.25 <i>M</i>_{<span>⊕</span>} inside the habitable zone of Sun-like stars can end up with He-dominated primordial atmospheres. This finding has important implications for the evolution of Earth-like habitats, as these thick helium-enriched primordial atmospheres can inhibit the habitability of these planets. The upcoming generation of giant telescopes, such as the Extremely Large Telescope, may enable us to observe and explore these atmospheres.</p>","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"51 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144269154","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}

{"title":"A transiting giant planet in orbit around a 0.2-solar-mass host star","authors":"Edward M. Bryant, Andrés Jordán, Joel D. Hartman, Daniel Bayliss, Elyar Sedaghati, Khalid Barkaoui, Jamila Chouqar, Francisco J. Pozuelos, Daniel P. Thorngren, Mathilde Timmermans, Jose Manuel Almenara, Igor V. Chilingarian, Karen A. Collins, Tianjun Gan, Steve B. Howell, Norio Narita, Enric Palle, Benjamin V. Rackham, Amaury H. M. J. Triaud, Gaspar Á. Bakos, Rafael Brahm, Melissa J. Hobson, Vincent Van Eylen, Pedro J. Amado, Luc Arnold, Xavier Bonfils, Artem Burdanov, Charles Cadieux, Douglas A. Caldwell, Victor Casanova, David Charbonneau, Catherine A. Clark, Kevin I. Collins, Tansu Daylan, Georgina Dransfield, Brice-Olivier Demory, Elsa Ducrot, Gareb Fernández-Rodríguez, Izuru Fukuda, Akihiko Fukui, Michaël Gillon, Rebecca Gore, Matthew J. Hooton, Kai Ikuta, Emmanuel Jehin, Jon M. Jenkins, Alan M. Levine, Colin Littlefield, Felipe Murgas, Kendra Nguyen, Hannu Parviainen, Didier Queloz, S. Seager, Daniel Sebastian, Gregor Srdoc, R. Vanderspek, Joshua N. Winn, Julien de Wit, Sebastián Zúñiga-Fernández","doi":"10.1038/s41550-025-02552-4","DOIUrl":"https://doi.org/10.1038/s41550-025-02552-4","url":null,"abstract":"<p>Planet formation models indicate that the formation of giant planets is substantially harder around low-mass stars due to the scaling of protoplanetary disc masses with stellar mass. The discovery of giant planets orbiting such low-mass stars thus imposes strong constraints on giant planet formation processes. Here we report the discovery of a transiting giant planet orbiting a 0.207 ± 0.011 <i>M</i>_{<span>⊙</span>} star. The planet, TOI-6894 b, has a mass and radius of <i>M</i>_P = 0.168 ± 0.022 <i>M</i>_J (53.4 ± 7.1 <i>M</i>_{<span>⊕</span>}) and <i>R</i>_P = 0.855 ± 0.022 <i>R</i>_J and probably includes 12 ± 2 <i>M</i>_{<span>⊕</span>} of metals. The discovery of TOI-6894 b highlights the need for a better understanding of giant planet formation mechanisms and the protoplanetary disc environments in which they occur. The extremely deep transits (17% depth) make TOI-6894 b one of the most accessible exoplanetary giants for atmospheric characterization observations, which will be key for fully interpreting the formation history of this notable system and for the study of atmospheric methane chemistry.</p>","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144211361","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}

{"title":"A temperate 10-Earth-mass exoplanet around the Sun-like star Kepler-725","authors":"L. Sun, S. Gu, X. Wang, J. H. M. M. Schmitt, P. Ioannidis, M. B. N. Kouwenhoven, J. Dou, G. Zhao","doi":"10.1038/s41550-025-02565-z","DOIUrl":"https://doi.org/10.1038/s41550-025-02565-z","url":null,"abstract":"<p>The detection of low-mass exoplanets (≤10 Earth masses (<i>M</i>_{<span>⊕</span>})) yields fundamental inputs for current theories of planet formation and evolution, and supplies critical information for the planned direct-imaging missions that aim to detect and characterize Earth-like planets in the habitable zones around solar-like stars. However, the most efficient detection techniques available for low-mass exoplanets (that is, photometric transit and radial velocity methods) are heavily biased towards the detection of short-period planets (for example, ≤100 days) and strongly favour late-type stars. Here we report the discovery of Kepler-725 c, a 10 ± 3 <i>M</i>_{<span>⊕</span>} exoplanet within the habitable zone of the late G-type dwarf Kepler-725. Through analysis of the transit timing variations of the relatively short-period (39.64 days) warm Jupiter Kepler-725 b, we find that Kepler-725 c has a period of 207.5 days and travels in an eccentric orbit (with an eccentricity of 0.44 ± 0.02 and an orbital semi-major axis of 0.674 ± 0.002 au), receiving a time-averaged insolation of 1.4 times the Earth’s value. This discovery demonstrates that the transit timing variation method enables the detection and accurate mass measurement of a super-Earth/mini-Neptune within a solar-like star’s habitable zone. Similar searches for such exoplanets could be conducted in other exoplanetary systems in the era of the Transiting Exoplanet Survey Satellite mission and upcoming PLAnetary Transits and Oscillations of stars and Earth 2.0 missions.</p>","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"81 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144202116","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}

{"title":"The origins of very-wide-orbit planets","authors":"","doi":"10.1038/s41550-025-02558-y","DOIUrl":"https://doi.org/10.1038/s41550-025-02558-y","url":null,"abstract":"Simulations show how the orbits of planets gravitationally scattered outward might be perturbed by passing stars within the star’s birth cluster, leading to the planets becoming stranded on wide orbits — such as hypothetical Planet Nine. These results lead to the prediction of a rich population of very-wide-orbit planets in the Galaxy.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"7 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144193026","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}

{"title":"SiO and a super-stellar C/O ratio in the atmosphere of the giant exoplanet WASP-121 b","authors":"Thomas M. Evans-Soma, David K. Sing, Joanna K. Barstow, Anjali A. A. Piette, Jake Taylor, Joshua D. Lothringer, Henrique Reggiani, Jayesh M. Goyal, Eva-Maria Ahrer, Nathan J. Mayne, Zafar Rustamkulov, Tiffany Kataria, Duncan A. Christie, Cyril Gapp, Jiayin Dong, Daniel Foreman-Mackey, Soichiro Hattori, Mark S. Marley","doi":"10.1038/s41550-025-02513-x","DOIUrl":"https://doi.org/10.1038/s41550-025-02513-x","url":null,"abstract":"<p>Refractory elements such as iron, magnesium and silicon can be detected in the atmospheres of ultrahot giant planets. This provides an opportunity to quantify the amount of refractory material accreted during formation, along with volatile gases and ices. However, simultaneous detections of refractories and volatiles have proved challenging, as the most prominent spectral features of associated atoms and molecules span a broad wavelength range. Here, using a single JWST observation of the ultrahot giant planet WASP-121 b, we report detections of H₂O (5.5–13.5<i>σ</i>), CO (10.8–12.8<i>σ</i>) and SiO (5.7–6.2<i>σ</i>) in the planet’s dayside atmosphere and CH₄ (3.1–5.1<i>σ</i>) in the nightside atmosphere. We measure super-stellar values for the atmospheric C/H, O/H, Si/H and C/O ratios, which point to the joint importance of pebbles and planetesimals in giant planet formation. The CH₄-rich nightside composition is also indicative of dynamical processes, such as strong vertical mixing, having a profound influence on the chemistry of ultrahot giant planets.</p>","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"16 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144193148","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}

{"title":"No certainty of a Milky Way–Andromeda collision","authors":"Till Sawala, Jehanne Delhomelle, Alis J. Deason, Carlos S. Frenk, Jenni Häkkinen, Peter H. Johansson, Atte Keitaanranta, Alexander Rawlings, Ruby Wright","doi":"10.1038/s41550-025-02563-1","DOIUrl":"https://doi.org/10.1038/s41550-025-02563-1","url":null,"abstract":"<p>It is commonly believed that our own Milky Way is on a collision course with the neighbouring Andromeda galaxy. As a result of their merger, predicted in around 5 billion years, the two large spiral galaxies that define the present Local Group would form a new elliptical galaxy. Here we consider the latest and most accurate observations by the Gaia and Hubble space telescopes, along with recent consensus mass estimates, to derive possible future scenarios and identify the main sources of uncertainty in the evolution of the Local Group over the next 10 billion years. We found that the next most massive Local Group member galaxies—namely, M33 and the Large Magellanic Cloud—distinctly and radically affect the Milky Way–Andromeda orbit. Although including M33 increases the merger probability, the orbit of the Large Magellanic Cloud runs perpendicular to the Milky Way–Andromeda orbit and makes their merger less probable. In the full system, we found that uncertainties in the present positions, motions and masses of all galaxies leave room for drastically different outcomes and a probability of close to 50% that there will be no Milky Way–Andromeda merger during the next 10 billion years. Based on the best available data, the fate of our Galaxy is still completely open.</p>","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"26 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144202117","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}