{
  "abstract": "Hot subdwarf stars of spectral types O and B (sdO/B) in binaries form as products of substantial mass loss near the tip of the red giant branch and offer powerful constraints on binary-star evolutionary models. However, details of some formation channels remain missing. We present a comprehensive analysis of the short-period binary population in the 500 pc volume-limited sample of hot subdwarfs, enabled by precise Gaia DR3 parallaxes. Besides 45 known binaries within 500 pc, this work identifies 50 new single-lined radial-velocity variable systems, 34 with orbital solutions with periods between 0.07 and 22 days. We derive an overall short-period binary fraction of 34.7 (+2.8/-2.9)% for the full sample of 301 hot subdwarfs within 500 pc, corrected for orbital inclination and detection efficiency. The newly solved binaries predominantly occupy the 1-20 day range, a parameter space previously under-represented in the literature. We identify five new reflection-effect systems, three ellipsoidal modulation systems, a newly solved HW Vir system, and a new triple candidate. The sdB and sdO binary fractions are similar, while the sdOB class shows a fraction roughly half that of sdB/sdO stars, with periods over one day, suggesting a different evolutionary pathway. Underluminous hot subdwarfs below the canonical extreme horizontal branch show a binary fraction comparable to other sdB/sdO stars but host only white dwarf companions, which are more massive and mainly found at periods under one day. We provide the first volume-complete birthrate estimates for sub-populations, determining a Galactic merger rate of 2.5+-1.5x10^-5 yr^-1 for sdO/B binaries, explaining no more than ~12% of the eHe-sdO population. We also derive birthrates for two SN Ia progenitor channels, finding hot subdwarf binaries could account for up to 2.5 (+0.7/-0.5)% of the observed Galactic SN Ia rate.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.27673",
  "author_total": 19,
  "authors": [
    {
      "name": "H. Dawson"
    },
    {
      "name": "M. Dorsch"
    },
    {
      "name": "J. Munday"
    },
    {
      "name": "S. Geier"
    },
    {
      "name": "F. Mattig"
    },
    {
      "name": "M. Pritzkuleit"
    },
    {
      "name": "D. Benitez-Palacios"
    },
    {
      "name": "M. Vučković"
    },
    {
      "name": "K. Deshmukh"
    },
    {
      "name": "A. Bhat"
    },
    {
      "name": "U. Heber"
    },
    {
      "name": "I. Pelisoli"
    },
    {
      "name": "R. Raddi"
    },
    {
      "name": "P. Fernandez-Schlosser"
    },
    {
      "name": "A. Durán-Reyes"
    },
    {
      "name": "E. Arancibia-Rojas"
    },
    {
      "name": "A. Bobrick"
    },
    {
      "name": "V. Schaffenroth"
    },
    {
      "name": "G. T. Jones"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1m2y3n584x15g.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.27673",
  "fulltext_url": null,
  "id": "1m2y3n584x15g",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.27673",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.SR"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2608.27673",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-27",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/1m2y3n584x15g.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:22Z",
      "native_id": "2608.27673",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.27673"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.SR",
      "subfield": "stellar"
    }
  ],
  "title": "A 500 pc volume-limited sample of hot subluminous stars III. The short-period binary population",
  "title_text": "A 500 pc volume-limited sample of hot subluminous stars III. The short-period binary population",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:22Z",
  "url": "https://research.draconitic.com/paper/1m2y3n584x15g",
  "venue": "arXiv",
  "versions": []
}