{
  "abstract": "We report an independent identification of the ultra metal-poor (UMP) star ($\\rm[Fe/H] =-4.06$) $Gaia$ DR3 $\\texttt{source_id}$ 4795913112968206720 (GDR3_479591) in the $Gaia$ mission's Blue and Red Photometer 'XP' spectro-photometric catalog. We combine multi-band photometry, astrometry, and high-resolution spectroscopy to confirm GDR3_479591 as a red giant-branch (RGB) star located at ${\\sim} 6\\,{\\rm kpc}$ from the Sun. Abundance analysis under local thermodynamic equilibrium reveals significant enhancements, relative to the solar level, in carbon ($\\rm[C/Fe] = +1.54$, after evolutionary correction for depletion in the RGB), nitrogen ($\\rm[N/Fe] = +2.64$), and oxygen ($\\rm[O/Fe] = +2.62$). The CNO-enhanced GDR3_479591 is thus one of only 5 UMP stars with a detected oxygen abundance. The CNO excess is accompanied by enhancements in several other light elements, such as Na, Mg, Al, and Si. We demonstrate that the chemical pattern of GDR3_479591 can be reproduced by the yields of a single Population~III 'faint' supernova with progenitor mass of $\\sim$21-to-28$\\,M_\\odot$ and a low explosion energy of ($0.3 \\leq E_{\\rm SN}/(10^{51}\\,{\\rm erg}) \\leq 0.9$). Additionally, we use literature metal-poor stars to show that, contrary to recent propositions for high-redshift galaxies, a mild enhancement in [C/O] does not automatically translate to the high [C/Fe] typically observed in UMP stars in the Milky Way and its satellites. GDR3_479591 could not be dynamically associated with any of the most relevant accreted substructures in the Galactic halo, and we speculate that it was formed in an ultra-faint dwarf galaxy environment that later merged with the Milky Way.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.13373",
  "author_total": 13,
  "authors": [
    {
      "name": "Guilherme Limberg"
    },
    {
      "name": "Vinicius M. Placco"
    },
    {
      "name": "Alexander P. Ji"
    },
    {
      "name": "Yupeng Yao"
    },
    {
      "name": "Friedrich Anders"
    },
    {
      "name": "Wendy Q. Sun"
    },
    {
      "name": "Anna de Graaff"
    },
    {
      "name": "Rohan P. Naidu"
    },
    {
      "name": "Harley Katz"
    },
    {
      "name": "Pierre N. Thibodeaux"
    },
    {
      "name": "Anirudh Chiti"
    },
    {
      "name": "Mohammad K. Mardini"
    },
    {
      "name": "Anna Frebel"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/db5me5nknes9f.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.13373",
  "fulltext_url": null,
  "id": "db5me5nknes9f",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.13373",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.GA"
    ],
    [
      "arxiv",
      "astro-ph.SR"
    ],
    [
      "openalex",
      "3103|Stellar, planetary, and galactic studies"
    ]
  ],
  "openalex": "W7214715212",
  "pdf_url": "https://arxiv.org/pdf/2609.13373",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-25",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/db5me5nknes9f.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:12Z",
      "native_id": "2609.13373",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.13373"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.SR",
      "subfield": "stellar"
    }
  ],
  "title": "Chemo-dynamical Analysis of a CNO-Enhanced Ultra Metal-poor Star ($\\rm[Fe/H] < -4$): Insights into Early Enrichment by Faint Population III Supernova",
  "title_text": "Chemo-dynamical Analysis of a CNO-Enhanced Ultra Metal-poor Star ([Fe/H] < −4): Insights into Early Enrichment by Faint Population III Supernova",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:12Z",
  "url": "https://research.draconitic.com/paper/db5me5nknes9f",
  "venue": "arXiv",
  "versions": []
}