{
  "abstract": "We present a homogeneous catalogue of ages, metallicities, distances, and reddenings for 5056 open clusters in the Unified Cluster Catalogue (UCC), derived uniformly from Gaia Data Release 3 (DR3) colour-magnitude diagrams via Bayesian nested sampling with PARSEC isochrones. Unlike previous large-scale catalogues, metallicity is fitted as a free parameter for every cluster rather than fixed or adopted from the literature: where available, Gaia XP spectrophotometric metallicities inform the fit (1201 clusters), while the remaining clusters are constrained by broad priors from Gaia parallaxes and the Schlegel-Finkbeiner-Davis dust map. No cluster is anchored to an external open-cluster parameter catalogue, and no per-cluster manual intervention is applied. A fit-quality metric, $η_{\\rm fit}$, identifies 3807 clusters (75 per cent) with reliable colour-magnitude solutions, spanning ages of 0.004-5.9 Gyr and distances out to 17 kpc. We validate the resulting parameters against six literature catalogues and, more critically, against independent high-resolution spectroscopic metallicities from OCCAM DR19: for 132 clusters in common we find a median absolute deviation of only 0.054 dex ($-0.021 \\pm 0.132$ dex mean offset), comparable to the intrinsic systematic uncertainty of isochrone-based metallicities. As a direct consequence of this fidelity, the radial metallicity gradient recovered from our XP-informed clusters ($-0.064$ dex kpc$^{-1}$) steepens towards the spectroscopically calibrated value ($-0.079$ dex kpc$^{-1}$) for the highest-quality subset - demonstrating that a purely photometric pipeline, built without reference to spectroscopy, recovers a physically meaningful abundance scale. The full catalogue and posterior chains are publicly released.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2605.23802",
  "author_total": 2,
  "authors": [
    {
      "name": "Olcay Plevne"
    },
    {
      "name": "Furkan Akbaba"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/61xscc6xd44zk.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2605.23802",
  "fulltext_url": null,
  "id": "61xscc6xd44zk",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2605.23802",
  "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"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2605.23802",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-13",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/61xscc6xd44zk.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:31Z",
      "native_id": "2605.23802",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2605.23802"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "Astrophysical Parameters of 5056 Open Star Clusters from Bayesian Nested Sampling with PARSEC Isochrones",
  "title_text": "Astrophysical Parameters of 5056 Open Star Clusters from Bayesian Nested Sampling with PARSEC Isochrones",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:31Z",
  "url": "https://research.draconitic.com/paper/61xscc6xd44zk",
  "venue": "arXiv",
  "versions": []
}