{
  "abstract": "Disintegrating rocky planets provide a rare opportunity to probe material escaping directly from intensely irradiated planetary surfaces. We present time-resolved, low-resolution ($R\\simeq600$) optical spectroscopy and complementary ground-based photometry of BD+05 4868 Ab. The in-transit spectra exhibit an additional unresolved absorption feature near the O I triplet at 7771.94, 7774.17, and 7775.39 Angstroms relative to the out-of-transit baseline. The feature has an equivalent width of $W_λ\\simeq1.4\\pm0.2$ Angstroms, a maximum differential depth of approximately 9%, and an apparent width of 13-16 Angstroms, comparable to the instrumental resolution. We interpret the feature as candidate O I absorption from an oxygen-bearing mineral-vapor outflow. The $3s\\,{}^5S^\\circ_2$ lower level of the triplet lies 9.146 eV above the ground state and cannot be appreciably populated in LTE at the reported planetary temperature, requiring non-LTE excitation. A one-zone forward model in which photoionization, O$^+$ recombination, radiative cascade, and radiative trapping populate the excited state reproduces the measured equivalent width and instrumentally broadened line profile. The model favors an atomic component with a projected extent larger than the narrow condensed-dust layer and permits gas-to-dust mass-loss ratios of order a few for representative ionizing irradiation. Stellar O I line-profile variations remain the principal alternative at the present spectral resolution. We therefore identify escaping O I as the preferred physical interpretation while retaining the designation candidate O I. High-resolution, phase-resolved spectroscopy can directly test this interpretation by resolving the individual triplet components.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.04986",
  "author_total": 2,
  "authors": [
    {
      "name": "Kody M. Walker"
    },
    {
      "name": "James C. Wallace II"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/a1v2j39kfp59k.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.04986",
  "fulltext_url": null,
  "id": "a1v2j39kfp59k",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.04986",
  "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.EP"
    ],
    [
      "openalex",
      "3103|Stellar, planetary, and galactic studies"
    ]
  ],
  "openalex": "W7220659532",
  "pdf_url": "https://arxiv.org/pdf/2610.04986",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/a1v2j39kfp59k.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:01Z",
      "native_id": "2610.04986",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.04986"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.EP",
      "subfield": "planetary"
    }
  ],
  "title": "Candidate O I 7774 Å Absorption from an Escaping Rock-Vapor Outflow of BD+05 4868 Ab",
  "title_text": "Candidate O I 7774 Å Absorption from an Escaping Rock-Vapor Outflow of BD+05 4868 Ab",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:01Z",
  "url": "https://research.draconitic.com/paper/a1v2j39kfp59k",
  "venue": "arXiv",
  "versions": []
}