{
  "abstract": "Two archival cases lack a transient-focused counterpart census: IceCube events that pass alert-grade cuts in final offline reconstruction but never generated a real-time notice, and the ultra-high-energy event KM3-230213A, whose published counterpart work characterizes catalogued blazars, not archival transients. This work applies one census to both. In the current IceCube public track release (IceTracks-DR2; 2008–2022, 1.64 million tracks), 290 events pass these cuts; an audit against the complete AMON notice record and the IceCat-1 alert catalog isolates six (50–115 TeV, 2019–2021) with no public alert or per-event catalog entry. Each error region was vetted against transient catalogs, ASAS-SN light curves, spectroscopic surveys, Gaia DR3 astrometry, X-ray archives, and Fermi-LAT flare states. Four of the six localization regions yield no viable archival counterpart; one contains only a chance-level LAT-steady BL Lac. The sixth contains AT 2021iis, a 420 mJy radio quasar at z = 1.6827 whose sustained optical brightening began 110 days before the 50 TeV event and was rising at its epoch, followed by mid-infrared brightening consistent with a dust echo; the window transient count is unremarkable ( p = 0.11). Applied to KM3-230213A (∼220 PeV), the census returns nulls, bounds the published candidates, and adds an ATLAS-detected, ASAS-SN-confirmed optical flare of PKS 0605−08 (1.9 Jy, z = 0.87, inside the 99% localization) peaking 35 days before the neutrino. Flare-rate statistics leave both coincidences modest (≈50% chance of a flare within ±40 days of any epoch), and a triggered search on its 2018 flare shows no IceCube excess. The products are the event catalog, the census methodology with documented public-interface failure modes, and two falsifiable candidates.",
  "abstract_shown": true,
  "affiliations": [
    "Ohio University"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 1,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "R. Tata",
      "orcid": "0009-0005-1055-5848"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/fk6f507xf9zqw.bib",
  "cited_by": 0,
  "doi": "10.3847/1538-4357/aeac26",
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  "id": "fk6f507xf9zqw",
  "issns": [
    "1538-4357",
    "0004-637X"
  ],
  "landing_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aeac26",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "feed-journal",
      "astronomy/general"
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      "openalex",
      "3106|Astrophysics and Cosmic Phenomena"
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  "pdf_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aeac26/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-28",
  "publisher": "American Astronomical Society",
  "ris": "https://research.draconitic.com/paper/fk6f507xf9zqw.ris",
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    {
      "first_seen": "2026-10-30T12:17:17Z",
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  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3106|Astrophysics and Cosmic Phenomena",
      "subfield": "high-energy"
    }
  ],
  "title": "Archival Counterpart Censuses for Never-alerted IceCube Events and the Ultra-high-energy Neutrino KM3-230213A",
  "title_text": "Archival Counterpart Censuses for Never-alerted IceCube Events and the Ultra-high-energy Neutrino KM3-230213A",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:11Z",
  "url": "https://research.draconitic.com/paper/fk6f507xf9zqw",
  "venue": "The Astrophysical Journal",
  "versions": []
}