Nature Astronomy最新文献_第4页

CHIME delivers a second haul CHIME带来了第二次收获

IF 14.3 1区物理与天体物理

Nature Astronomy Pub Date : 2026-03-23 DOI: 10.1038/s41550-026-02827-4

Paul Woods

引用次数: 0

The threat of satellite constellations to developing countries such as Indonesia 卫星星座对印度尼西亚等发展中国家的威胁

IF 14.3 1区物理与天体物理

Nature Astronomy Pub Date : 2026-03-23 DOI: 10.1038/s41550-026-02810-z

Antonia Rahayu Rosaria Wibowo, Dicky Wahyudy

引用次数: 0

Volatile-rich evolution of molten super-Earth L 98-59 d 熔融超级地球L 98-59 d的富挥发物演化

IF 14.1 1区物理与天体物理

Nature Astronomy Pub Date : 2026-03-16 DOI: 10.1038/s41550-026-02815-8

Harrison Nicholls, Tim Lichtenberg, Richard D. Chatterjee, Claire Marie Guimond, Emma Postolec, Raymond T. Pierrehumbert

{"title":"Volatile-rich evolution of molten super-Earth L 98-59 d","authors":"Harrison Nicholls, Tim Lichtenberg, Richard D. Chatterjee, Claire Marie Guimond, Emma Postolec, Raymond T. Pierrehumbert","doi":"10.1038/s41550-026-02815-8","DOIUrl":"https://doi.org/10.1038/s41550-026-02815-8","url":null,"abstract":"Small, low-density exoplanets are sculpted by strong stellar irradiation, but their primordial compositions and subsequent evolution are still unknown. Two often-considered scenarios hold that they formed with rocky interiors and H2–He atmospheres (‘gas dwarfs’) or alternatively with bulk compositions dominated by H2O phases (‘water worlds’). Here we constrain the possible range of evolutionary histories linking the birth conditions of low-density super-Earth L 98-59 d to recent observations using a coupled atmosphere–interior evolutionary model. We find that the observations can be explained by in situ photochemical production of SO2 in an H2 background, indicative of a chemically reducing mantle and substantial (>1.8 mass%) early sulfur and hydrogen content, inconsistent with both the gas-dwarf and water-world scenarios. L 98-59 d’s interior comprises a permanent magma ocean, allowing long-term retention of volatiles within its mantle over billions of years, consistent with California-Kepler Survey trends. Our analysis reveals an evolutionary pathway in which planets host volatile-rich atmospheres sustained by long-term magma-ocean degassing, shaped by secular cooling, atmospheric erosion and photochemistry. Internal and environmental processes contribute to the observed diversity of super-Earth and sub-Neptune exoplanets.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"20 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147465277","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

Enrichment by the first stars in a relic dwarf galaxy 遗迹矮星系中第一批恒星的富集

IF 14.1 1区物理与天体物理

Nature Astronomy Pub Date : 2026-03-16 DOI: 10.1038/s41550-026-02802-z

Anirudh Chiti, Vinicius M. Placco, Andrew B. Pace, Alexander P. Ji, Deepthi S. Prabhu, William Cerny, Guilherme Limberg, Guy S. Stringfellow, Alex Drlica-Wagner, Kaia R. Atzberger, Yumi Choi, Denija Crnojević, Peter S. Ferguson, Nitya Kallivayalil, Noelia E. D. Noël, Alexander H. Riley, David J. Sand, Joshua D. Simon, Alistair R. Walker, Clecio R. Bom, Julio A. Carballo-Bello, David J. James, Clara E. Martínez-Vázquez, Gustavo E. Medina, A. Katherina Vivas

{"title":"Enrichment by the first stars in a relic dwarf galaxy","authors":"Anirudh Chiti, Vinicius M. Placco, Andrew B. Pace, Alexander P. Ji, Deepthi S. Prabhu, William Cerny, Guilherme Limberg, Guy S. Stringfellow, Alex Drlica-Wagner, Kaia R. Atzberger, Yumi Choi, Denija Crnojević, Peter S. Ferguson, Nitya Kallivayalil, Noelia E. D. Noël, Alexander H. Riley, David J. Sand, Joshua D. Simon, Alistair R. Walker, Clecio R. Bom, Julio A. Carballo-Bello, David J. James, Clara E. Martínez-Vázquez, Gustavo E. Medina, A. Katherina Vivas","doi":"10.1038/s41550-026-02802-z","DOIUrl":"https://doi.org/10.1038/s41550-026-02802-z","url":null,"abstract":"Stars that contain trace amounts of elements heavier than helium (that is, ‘metallicity’) preserve the chemical fingerprints of the first stars. In the Milky Way, nearly all of the lowest-metallicity stars show an extreme over-abundance of carbon. The origin of this signature has remained a mystery owing to the lack of observational constraints on the environments in which it originates. Here we present observations of a star in the >10-billion-year-old ultrafaint dwarf galaxy Pictor II, showing the lowest iron and calcium abundances outside the Milky Way (<1/43,000th solar and ~1/160,000th solar), with >3,000× relative carbon enhancement. The star’s exceptional paucity in iron and calcium make it clearly preserve enrichment from the first stars in a relic dwarf galaxy; Pictor II is one of the smallest, most chemically primordial systems known. This star supports the hypothesis that extreme carbon enhancement results from low-energy supernovae from the first stars, as the yields of energetic supernovae are harder to retain in small-scale environments. This signature of enrichment by the first stars may trace a regime inaccessible to current high-redshift observations, which can hardly detect the initial enrichment of the smallest galaxies.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"49 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147465276","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 complete set of canonical nucleobases in the carbonaceous asteroid (162173) Ryugu 碳质小行星（162173）龙宫的一整套典型核碱基

IF 14.1 1区物理与天体物理

Nature Astronomy Pub Date : 2026-03-16 DOI: 10.1038/s41550-026-02791-z

Toshiki Koga, Yasuhiro Oba, Yoshinori Takano, Hiroshi Naraoka, Nanako O. Ogawa, Kazunori Sasaki, Hajime Sato, Toshihiro Yoshimura, Naohiko Ohkouchi

{"title":"A complete set of canonical nucleobases in the carbonaceous asteroid (162173) Ryugu","authors":"Toshiki Koga, Yasuhiro Oba, Yoshinori Takano, Hiroshi Naraoka, Nanako O. Ogawa, Kazunori Sasaki, Hajime Sato, Toshihiro Yoshimura, Naohiko Ohkouchi","doi":"10.1038/s41550-026-02791-z","DOIUrl":"https://doi.org/10.1038/s41550-026-02791-z","url":null,"abstract":"Organic molecules delivered from extraterrestrial materials may have played a key role in supplying building blocks for life on Earth. Here we report all five canonical nucleobases—purines (adenine and guanine) and pyrimidines (cytosine, thymine and uracil)—in samples returned from the C-type asteroid (162173) Ryugu by JAXA’s Hayabusa2 mission and compare the results with data from similar extraterrestrial material. Ryugu samples contain nearly equal amounts of purines and pyrimidines, whereas Murchison is enriched in purines and Bennu and Orgueil in pyrimidines. Samples from Ryugu, Bennu and Orgueil, which have a similar mineralogy and elemental composition, show purine-to-pyrimidine ratios negatively correlating with ammonia. These observations indicate that the nucleobases in these samples may have formed via a shared pathway depending on the physicochemical environment of the respective parent bodies. The detection of diverse nucleobases in asteroid and meteorite materials demonstrates their widespread presence throughout the Solar System and reinforces the hypothesis that carbonaceous asteroids contributed to the prebiotic chemical inventory of early Earth.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"42 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147465278","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

Star formation in the circumgalactic high-velocity cloud Complex H 环银河系高速云复合体H中的恒星形成

IF 14.1 1区物理与天体物理

Nature Astronomy Pub Date : 2026-03-11 DOI: 10.1038/s41550-026-02814-9

Zhihong He, Wenkang Pang, Kun Wang, Yangping Luo, Qian Cui

{"title":"Star formation in the circumgalactic high-velocity cloud Complex H","authors":"Zhihong He, Wenkang Pang, Kun Wang, Yangping Luo, Qian Cui","doi":"10.1038/s41550-026-02814-9","DOIUrl":"https://doi.org/10.1038/s41550-026-02814-9","url":null,"abstract":"The accretion of metal-poor gas sustains galactic star formation. In the Milky Way, this process is fuelled by high-velocity clouds (HVCs), but their fundamental properties have remained elusive in the absence of stellar tracers. Here we report a binary open cluster within HVC Complex H. With an age of 11.2 ± 0.6 Myr and a subsolar metallicity of (0.0{5}_{-0.02}^{+0.05}) Z⊙, the clusters provide a direct stellar distance anchor to the cloud at 13.8 ± 0.6 kpc. Their proper motions indicate that Complex H is on a prograde, south-to-north orbit through the outer Galactic disk. The resulting interaction produces a ‘slow–fast–slow’ velocity gradient, with the cloud’s outer layers decelerating as they merge into the disk. Orbit integration suggests that the clusters formed from an internal cloud–cloud collision. This triggering mechanism implies that other HVCs could similarly produce high-velocity stars. The scarcity of previous stellar detections in HVCs is explained by the rapid escape of young stars (<20 Myr), whereas CO non-detections may stem from weak emission due to low metallicity and gas dispersal. This work reveals that the circumgalactic medium can sustain star formation, offering a tangible laboratory to probe the physical conditions of accreting gas before it merges with the Galactic disk.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"55 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147394042","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 broad perspective on Galactic life 对银河系生命的广阔视角

IF 14.3 1区物理与天体物理

Nature Astronomy Pub Date : 2026-03-11 DOI: 10.1038/s41550-026-02803-y

Gibor Basri

{"title":"A broad perspective on Galactic life","authors":"Gibor Basri","doi":"10.1038/s41550-026-02803-y","DOIUrl":"10.1038/s41550-026-02803-y","url":null,"abstract":"One of the most active areas in current astrophysics is the search for clues to answering the ancient question: are we alone? This Perspective focuses on where most of the life in our Galaxy might reside over the very long haul, taking a freer viewpoint than is typical for astrobiology. The astrophysical discussion includes stellar numbers and longevity, planetary numbers and conditions, and the effects of stellar magnetic activity. I support the position that exoplanets in habitable zones around stars of between 0.5 and 0.8 solar masses might be the dominant habitats for surface life. However, the primary habitat in the Galaxy could easily be salty oceans under thick ice shells instead. These are probably much more numerous than planets with Earth-like conditions and have little dependence on stellar properties. In both cases, exoplanets of a few Earth masses are favoured for several reasons. These conclusions are based on terrestrial life, but there is no reason to think that nature is confined to that paradigm, so I discuss some other speculative possibilities. Finally, I suggest that the classical Drake equation should be made dynamic to reflect galactic evolution, and discuss the importance of survival times for life and civilizations. Scientists asking whether we are alone now see promising habitats in Earth-like worlds orbiting small stars and in deep oceans under thick ice layers, hinting that life may be common and that our old ways of estimating its prevalence need a rethink.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"10 3","pages":"357-362"},"PeriodicalIF":14.3,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147507825","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

What understanding means in AI-laden astronomy 在充满人工智能的天文学中，理解意味着什么

IF 14.3 1区物理与天体物理

Nature Astronomy Pub Date : 2026-03-11 DOI: 10.1038/s41550-026-02809-6

Yuan-Sen Ting, André Curtis-Trudel, Siyu Yao

引用次数: 0

Worlds between Earth and Neptune defy a simple story 地球和海王星之间的世界不符合一个简单的故事

IF 14.3 1区物理与天体物理

Nature Astronomy Pub Date : 2026-03-10 DOI: 10.1038/s41550-026-02812-x

Caroline Morley

引用次数: 0

Exascale computing to accelerate discoveries in astrophysics and space plasma physics 百亿亿次计算加速天体物理学和空间等离子体物理学的发现

IF 14.3 1区物理与天体物理

Nature Astronomy Pub Date : 2026-03-10 DOI: 10.1038/s41550-026-02807-8

Nitin Shukla, Geray S. Karademir, Luciano Rezzolla, Fabio Bacchini, Stefano Truzzi, Andrea Mignone, Alessandro Romeo, Klaus Dolag, Luca Tornatore, Lubomir Riha, Giuliano Taffoni

引用次数: 0