{
  "abstract": "Interstellar objects provide a unique opportunity to deepen our understanding of planetary formation by enabling detailed study of material formed around other stars. Their ices contain precious clues about the environment and conditions prevailing in their home system. As fractionation processes can be sensitive to the temperature and radiation environment, isotopic ratios are powerful tracers of the origin and evolution of different species. While isotopic ratios have been measured in Solar System comets, previously detected interstellar objects have been too faint to measure isotopic ratios. Here we report the measurement of two ratios in 3I/ATLAS from observations of the CN molecule: 12 C/ 13 C = $${151}_{-44}^{+110}$$ 151 - 44 + 110 and 14 N/ 15 N = $$36{3}_{-153}^{+633}$$ 36 3 − 153 + 633 . The 14 N/ 15 N is higher than the value of ~150 usually measured for Solar System comets, close to the values measured in the interstellar medium, prestellar phases or outside of protoplanetary disks. The 12 C/ 13 C is higher than the values usually measured for Solar System comets and in the local interstellar medium. These measurements are compatible with an origin of 3I in the outer disk around an older low-metallicity star, providing potential insights into the likelihood and efficiency of planetesimal formation around such stars.",
  "abstract_shown": true,
  "affiliations": [
    "Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, UK",
    "STAR Institute, University of Liège, Liège (Sart-Tilman), Belgium",
    "Volgenau Department of Physics, United States Naval Academy, Annapolis, MD, USA",
    "Faculty of Science and Engineering, Northumbria University, Newcastle, UK",
    "Physics Department, Edmund C. Leach Science Center, Auburn University, Auburn, AL, USA",
    "Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Macul, Chile",
    "Millennium Nucleus on Young Exoplanets and their Moons (YEMS), Santiago, Chile",
    "Astrochemistry Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, USA",
    "Department of Physics, Catholic University of America, Washington, DC, USA",
    "Department of Physics, University of Helsinki, Helsinki, Finland",
    "Department of Physics and Astronomy, University of Padova, Padova, Italy",
    "INAF – Osservatorio Astrofisico di Arcetri, Florence, Italy",
    "School of Physical and Chemical Sciences – Te Kura Matū, University of Canterbury, Christchurch, New Zealand"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 16,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Cyrielle Opitom",
      "orcid": "0000-0002-9298-7484"
    },
    {
      "affs": [
        1
      ],
      "name": "Jean Manfroid",
      "orcid": "0000-0002-6930-2205"
    },
    {
      "affs": [
        1
      ],
      "name": "Damien Hutsemékers"
    },
    {
      "affs": [
        1
      ],
      "name": "Emmanuël Jehin",
      "orcid": "0000-0001-8923-488X"
    },
    {
      "affs": [
        2
      ],
      "name": "Matthew M. Knight",
      "orcid": "0000-0003-2781-6897"
    },
    {
      "affs": [
        1
      ],
      "name": "Krishnakumar Aravind",
      "orcid": "0000-0002-8328-5667"
    },
    {
      "affs": [
        3
      ],
      "name": "Léa Ferellec",
      "orcid": "0000-0002-2088-3889"
    },
    {
      "affs": [
        4
      ],
      "name": "Dennis Bodewits",
      "orcid": "0000-0002-2668-7248"
    },
    {
      "affs": [
        5,
        6
      ],
      "name": "Viviana Veloso Guzmán",
      "orcid": "0000-0003-4784-3040"
    },
    {
      "affs": [
        7,
        8
      ],
      "name": "Martin Cordiner",
      "orcid": "0000-0001-8233-2436"
    },
    {
      "affs": [
        9
      ],
      "name": "Rosemary C. Dorsey",
      "orcid": "0000-0002-8910-1021"
    },
    {
      "affs": [
        10
      ],
      "name": "Fiorangela La Forgia",
      "orcid": "0000-0003-3924-1867"
    },
    {
      "affs": [
        11
      ],
      "name": "Manuela Lippi",
      "orcid": "0000-0001-9185-878X"
    },
    {
      "affs": [
        0
      ],
      "name": "B. P. Murphy"
    },
    {
      "affs": [
        0
      ],
      "name": "C. Snodgrass",
      "orcid": "0000-0001-9328-2905"
    },
    {
      "affs": [
        12
      ],
      "name": "Michele Bannister",
      "orcid": "0000-0003-3257-4490"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/858pq7sk6yv8g.bib",
  "cited_by": 19,
  "doi": "10.1038/s41550-026-02921-7",
  "fulltext_url": null,
  "id": "858pq7sk6yv8g",
  "issns": [
    "2397-3366"
  ],
  "landing_url": "https://doi.org/10.1038/s41550-026-02921-7",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
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      "openalex",
      "1912|Astro and Planetary Science"
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  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-07-06",
  "publisher": "Nature Portfolio",
  "ris": "https://research.draconitic.com/paper/858pq7sk6yv8g.ris",
  "sources": [
    {
      "first_seen": "2026-11-06T13:20:41Z",
      "native_id": "W7167489819",
      "source": "openalex",
      "url": "https://doi.org/10.1038/s41550-026-02921-7"
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  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:1912|Astro and Planetary Science",
      "subfield": "planetary"
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  ],
  "title": "High nitrogen and carbon isotopic ratios in the interstellar comet 3I/ATLAS",
  "title_text": "High nitrogen and carbon isotopic ratios in the interstellar comet 3I/ATLAS",
  "type": "peer-reviewed",
  "updated_at": "2026-11-09T13:21:19Z",
  "url": "https://research.draconitic.com/paper/858pq7sk6yv8g",
  "venue": "Nature Astronomy",
  "versions": []
}