{
  "abstract": "The interstellar comet 3I/ATLAS exhibits unusual polarimetric properties compared with Solar System comets, while constraints on its fundamental physical properties, such as dust albedo and grain-size distribution, remain limited. We obtained new optical polarimetry near opposition with the Pirka Telescope, combined it with previously reported polarimetric measurements, and constructed a visible-to-mid-infrared spectral energy distribution (SED) from HST, VLT, SPHEREx, and JWST observations. The SED indicates that the coma is dominated by dark, absorbing dust, with an effective V-band albedo of $p_{\\rm eff}\\sim0.04$. Modeling the SED with a power-law grain-size distribution yields a size index of $q=3.0$--$3.3$. The mid-infrared spectral structure is better reproduced by adding a minor amorphous-silicate component. The combined polarimetric data further favor a highly porous scattering structure. Despite its unusual polarimetric behavior, the dust of 3I/ATLAS has an albedo and grain-size distribution within the range found for Solar System comets.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.04919",
  "author_total": 16,
  "authors": [
    {
      "name": "Seungwon Choi"
    },
    {
      "name": "Masateru Ishiguro"
    },
    {
      "name": "Hiroyuki Naito"
    },
    {
      "name": "Yoonsoo P. Bach"
    },
    {
      "name": "Jooyeon Geem"
    },
    {
      "name": "Bumhoo Lim"
    },
    {
      "name": "Moonkuk Hur"
    },
    {
      "name": "Sihu Ahn"
    },
    {
      "name": "Sunho Jin"
    },
    {
      "name": "Hisayuki Kubota"
    },
    {
      "name": "Seiko Takagi"
    },
    {
      "name": "Tatsuharu Ono"
    },
    {
      "name": "Max Mahlke"
    },
    {
      "name": "Carey Lisse"
    },
    {
      "name": "Tomohiko Sekiguchi"
    },
    {
      "name": "Makoto Watanabe"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/cqwsjz6cj30z2.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.04919",
  "fulltext_url": null,
  "id": "cqwsjz6cj30z2",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.04919",
  "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.EP"
    ],
    [
      "arxiv",
      "astro-ph.GA"
    ],
    [
      "openalex",
      "3103|Astro and Planetary Science"
    ]
  ],
  "openalex": "W7220737784",
  "pdf_url": "https://arxiv.org/pdf/2610.04919",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/cqwsjz6cj30z2.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:01Z",
      "native_id": "2610.04919",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.04919"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.EP",
      "subfield": "planetary"
    }
  ],
  "title": "Spectral Energy Distribution and Polarimetric Properties of Dust in the Interstellar Comet 3I/ATLAS",
  "title_text": "Spectral Energy Distribution and Polarimetric Properties of Dust in the Interstellar Comet 3I/ATLAS",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:01Z",
  "url": "https://research.draconitic.com/paper/cqwsjz6cj30z2",
  "venue": "arXiv",
  "versions": []
}