{
  "abstract": "Nitrogen-rich (N-rich) field stars (likely second-generation escapees from globular clusters) provide a powerful, but currently sample-limited, probe of globular-cluster disruption in the Galactic halo. We exploit the fact that enhanced NH, CN absorption depresses optical u band flux, while the near-ultraviolet (NUV) band is largely insensitive to nitrogen enhancement while remaining sensitive to overall metallicity. Combining GALEX NUV photometry with (synthetic) SDSS optical photometry, we construct a [Fe/H]-dependent stellar-locus model for giants and select significant redder u-g outliers as N-rich candidates. For a relaxed cut ([Fe/H] <= -0.8, 2 sigma) we identify 970 candidates, with an estimated completeness of 64-65% and purity of 41-62% from multiple validations. A stricter selection ([Fe/H] <= -1.0, 3 sigma) yields 220 candidates, with lower completeness (30-38%) but substantially higher purity (60-91%). The dominant contaminants show anomalous spectral energy distributions (e.g., UV excess), and are themselves useful targets for follow-up. The diverse kinematic and dynamical properties of our candidates suggest multiple origins. This scalable photometric approach enables systematic searches for N-rich halo stars and is well suited to forthcoming wide-field surveys such as CSST.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.29706",
  "author_total": 6,
  "authors": [
    {
      "name": "Liangyu Yu"
    },
    {
      "name": "Haibo Yuan"
    },
    {
      "name": "Baitian Tang"
    },
    {
      "name": "Kai Xiao"
    },
    {
      "name": "Xue Lu"
    },
    {
      "name": "José G. Fernández-Trincado"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1gjxh7zkb53qf.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.29706",
  "fulltext_url": null,
  "id": "1gjxh7zkb53qf",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.29706",
  "language": null,
  "licence": "CC0-1.0",
  "licence_label": "CC0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/publicdomain/zero/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.GA"
    ],
    [
      "arxiv",
      "astro-ph.SR"
    ],
    [
      "openalex",
      "3103|Stellar, planetary, and galactic studies"
    ]
  ],
  "openalex": "W7223227931",
  "pdf_url": "https://arxiv.org/pdf/2610.29706",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-21",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/1gjxh7zkb53qf.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:19Z",
      "native_id": "2610.29706",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.29706"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.SR",
      "subfield": "stellar"
    }
  ],
  "title": "Stellar Loci X: Selection of Nitrogen-Rich Giants Using GALEX NUV and Synthetic SDSS Photometry",
  "title_text": "Stellar Loci X: Selection of Nitrogen-Rich Giants Using GALEX NUV and Synthetic SDSS Photometry",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:19Z",
  "url": "https://research.draconitic.com/paper/1gjxh7zkb53qf",
  "venue": "arXiv",
  "versions": []
}