R. O. Parke Loyd, Ethan Schreyer, James E. Owen, James G. Rogers, Madelyn I. Broome, Evgenya L. Shkolnik, Ruth Murray-Clay, David J. Wilson, Sarah Peacock, Johanna Teske, Hilke E. Schlichting, Girish M. Duvvuri, Allison Youngblood, P. Christian Schneider, Kevin France, Steven Giacalone, Natasha E. Batalha, Adam C. Schneider, Isabella Longo, Travis Barman, David R. Ardila
{"title":"氢从一对比海王星小的系外行星中逃逸","authors":"R. O. Parke Loyd, Ethan Schreyer, James E. Owen, James G. Rogers, Madelyn I. Broome, Evgenya L. Shkolnik, Ruth Murray-Clay, David J. Wilson, Sarah Peacock, Johanna Teske, Hilke E. Schlichting, Girish M. Duvvuri, Allison Youngblood, P. Christian Schneider, Kevin France, Steven Giacalone, Natasha E. Batalha, Adam C. Schneider, Isabella Longo, Travis Barman, David R. Ardila","doi":"10.1038/s41586-024-08490-x","DOIUrl":null,"url":null,"abstract":"Exoplanet surveys have shown a class of abundant exoplanets smaller than Neptune on close, <100-day orbits1–4. These planets form two populations separated by a natural division at about 1.8 R⊕ termed the radius valley. It is uncertain whether these populations arose from separate dry versus water-rich formation channels, evolved apart because of long-term atmospheric loss or a combination of both5–14. Here we report observations of ongoing hydrogen loss from two sibling planets, TOI-776 b (1.85 ± 0.13 R⊕) and TOI-776 c (2.02 ± 0.14 R⊕), the sizes of which near the radius valley and mature (1–4 Gyr) age make them valuable for investigating the origins of the divided population of which they are a part. During the transits of these planets, absorption appeared against the Lyman-α emission of the host star, compatible with hydrogen escape at rates equivalent to 0.03–0.6% and 0.1–0.9% of the total mass per billion years of each planet, respectively. Observations of the outer planet, TOI-776 c, are incompatible with an outflow of dissociated steam, suggesting both it and its inner sibling formed in a dry environment. These observations support the strong role of hydrogen loss in the evolution of close-orbiting sub-Neptunes5–8,15,16. Ongoing hydrogen loss from two sibling exoplanets provides support for the role of such hydrogen loss in the evolution of close-orbiting sub-Neptunes.","PeriodicalId":18787,"journal":{"name":"Nature","volume":"638 8051","pages":"636-639"},"PeriodicalIF":48.5000,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Hydrogen escaping from a pair of exoplanets smaller than Neptune\",\"authors\":\"R. O. Parke Loyd, Ethan Schreyer, James E. Owen, James G. Rogers, Madelyn I. Broome, Evgenya L. Shkolnik, Ruth Murray-Clay, David J. Wilson, Sarah Peacock, Johanna Teske, Hilke E. Schlichting, Girish M. Duvvuri, Allison Youngblood, P. Christian Schneider, Kevin France, Steven Giacalone, Natasha E. Batalha, Adam C. Schneider, Isabella Longo, Travis Barman, David R. Ardila\",\"doi\":\"10.1038/s41586-024-08490-x\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Exoplanet surveys have shown a class of abundant exoplanets smaller than Neptune on close, <100-day orbits1–4. These planets form two populations separated by a natural division at about 1.8 R⊕ termed the radius valley. It is uncertain whether these populations arose from separate dry versus water-rich formation channels, evolved apart because of long-term atmospheric loss or a combination of both5–14. Here we report observations of ongoing hydrogen loss from two sibling planets, TOI-776 b (1.85 ± 0.13 R⊕) and TOI-776 c (2.02 ± 0.14 R⊕), the sizes of which near the radius valley and mature (1–4 Gyr) age make them valuable for investigating the origins of the divided population of which they are a part. During the transits of these planets, absorption appeared against the Lyman-α emission of the host star, compatible with hydrogen escape at rates equivalent to 0.03–0.6% and 0.1–0.9% of the total mass per billion years of each planet, respectively. Observations of the outer planet, TOI-776 c, are incompatible with an outflow of dissociated steam, suggesting both it and its inner sibling formed in a dry environment. These observations support the strong role of hydrogen loss in the evolution of close-orbiting sub-Neptunes5–8,15,16. Ongoing hydrogen loss from two sibling exoplanets provides support for the role of such hydrogen loss in the evolution of close-orbiting sub-Neptunes.\",\"PeriodicalId\":18787,\"journal\":{\"name\":\"Nature\",\"volume\":\"638 8051\",\"pages\":\"636-639\"},\"PeriodicalIF\":48.5000,\"publicationDate\":\"2025-02-12\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Nature\",\"FirstCategoryId\":\"103\",\"ListUrlMain\":\"https://www.nature.com/articles/s41586-024-08490-x\",\"RegionNum\":1,\"RegionCategory\":\"综合性期刊\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MULTIDISCIPLINARY SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nature","FirstCategoryId":"103","ListUrlMain":"https://www.nature.com/articles/s41586-024-08490-x","RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MULTIDISCIPLINARY SCIENCES","Score":null,"Total":0}
Hydrogen escaping from a pair of exoplanets smaller than Neptune
Exoplanet surveys have shown a class of abundant exoplanets smaller than Neptune on close, <100-day orbits1–4. These planets form two populations separated by a natural division at about 1.8 R⊕ termed the radius valley. It is uncertain whether these populations arose from separate dry versus water-rich formation channels, evolved apart because of long-term atmospheric loss or a combination of both5–14. Here we report observations of ongoing hydrogen loss from two sibling planets, TOI-776 b (1.85 ± 0.13 R⊕) and TOI-776 c (2.02 ± 0.14 R⊕), the sizes of which near the radius valley and mature (1–4 Gyr) age make them valuable for investigating the origins of the divided population of which they are a part. During the transits of these planets, absorption appeared against the Lyman-α emission of the host star, compatible with hydrogen escape at rates equivalent to 0.03–0.6% and 0.1–0.9% of the total mass per billion years of each planet, respectively. Observations of the outer planet, TOI-776 c, are incompatible with an outflow of dissociated steam, suggesting both it and its inner sibling formed in a dry environment. These observations support the strong role of hydrogen loss in the evolution of close-orbiting sub-Neptunes5–8,15,16. Ongoing hydrogen loss from two sibling exoplanets provides support for the role of such hydrogen loss in the evolution of close-orbiting sub-Neptunes.
期刊介绍:
Nature is a prestigious international journal that publishes peer-reviewed research in various scientific and technological fields. The selection of articles is based on criteria such as originality, importance, interdisciplinary relevance, timeliness, accessibility, elegance, and surprising conclusions. In addition to showcasing significant scientific advances, Nature delivers rapid, authoritative, insightful news, and interpretation of current and upcoming trends impacting science, scientists, and the broader public. The journal serves a dual purpose: firstly, to promptly share noteworthy scientific advances and foster discussions among scientists, and secondly, to ensure the swift dissemination of scientific results globally, emphasizing their significance for knowledge, culture, and daily life.