{
  "abstract": "Supernova (SN) 1987A showed that some hydrogen-rich core-collapse supernovae (SNe) rise slowly to peak, defining a distinct subclass. Wide-field surveys have uncovered more extreme members, such as OGLE-2014-SN-73, SN 2020faa, and SN 2023vbw, that challenge neutrino-driven explosion models. We present ultraviolet-to-infrared, radio, X-ray, and spectropolarimetric observations of SN 2023iop at $z = 0.1020$, the most extreme 87A-like event to date. It rose for $\\gtrsim88$ rest-frame days to $M_r \\approx -20.1$ mag, also placing it among the hydrogen-rich superluminous SNe, and radiated $\\gtrsim4\\times10^{50}$ erg. Its spectra resemble those of typical Type II SNe and remain photospheric at $\\sim330$ days post-maximum. Continuum polarization of 0.8-1.0% indicates an aspherical system. Hydrogen-rich pair-instability supernova (PISN) models of a $190~M_\\odot$ star reproduce the light-curve up to 150 days after peak, but not the late-time emission. A late-time spectrum shows a feature near 7300 Å, tentatively identified as [Ni II] $λ$7378. The implied $\\approx0.02~M_\\odot$ of stable $^{58}$Ni is reached only in the most massive PISN models. The low-mass host galaxy ($\\sim10^{8.2}~M_\\odot$) is consistent with a metal-poor progenitor as required by the PISN channel. Fallback accretion reproduces the light-curve morphology, but not the colors. We consider a pair-instability explosion the most plausible scenario, with the late-time light-curve excess powered by circumstellar interaction, which shows no signatures in the spectra. SN 2023iop shows that the most luminous 87A-like events occupy an underexplored region of massive-star evolution.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.27312",
  "author_total": 72,
  "authors": [
    {
      "name": "Steve Schulze"
    },
    {
      "name": "Avinash Singh"
    },
    {
      "name": "Nikhil Sarin"
    },
    {
      "name": "Ofer Yaron"
    },
    {
      "name": "Jesper Sollerman"
    },
    {
      "name": "Takashi J. Moriya"
    },
    {
      "name": "Avishay Gal-Yam"
    },
    {
      "name": "Bart van Baal"
    },
    {
      "name": "Stan Barmentloo"
    },
    {
      "name": "Conor M. B. Omand"
    },
    {
      "name": "Hannah Wichern"
    },
    {
      "name": "Tuomas Kangas"
    },
    {
      "name": "Priscila J. Pessi"
    },
    {
      "name": "Adam A. Miller"
    },
    {
      "name": "Armin Rest"
    },
    {
      "name": "Lin Yan"
    },
    {
      "name": "Alexei V. Filippenko"
    },
    {
      "name": "Chang Liu"
    },
    {
      "name": "Miika Pursiainen"
    },
    {
      "name": "Yi Yang"
    },
    {
      "name": "Georgios Dimitriadis"
    },
    {
      "name": "Kishalay De"
    },
    {
      "name": "Seán J. Brennan"
    },
    {
      "name": "Thomas G. Brink"
    },
    {
      "name": "Ping Chen"
    },
    {
      "name": "Aleksandar Cikota"
    },
    {
      "name": "Felice Cusano"
    },
    {
      "name": "Nicholas Earley"
    },
    {
      "name": "Claes Fransson"
    },
    {
      "name": "Lluís Galbany"
    },
    {
      "name": "Anamaria Gkini"
    },
    {
      "name": "Anders Jerkstrand"
    },
    {
      "name": "Ragnhild Lunnan"
    },
    {
      "name": "Keiichi Maeda"
    },
    {
      "name": "Diego Paris"
    },
    {
      "name": "Andrea Rossi"
    },
    {
      "name": "Nabeel Rehemtulla"
    },
    {
      "name": "Claudia Skoglund"
    },
    {
      "name": "WeiKang Zheng"
    },
    {
      "name": "Alaa Alburai"
    },
    {
      "name": "Ke-Jung Chen"
    },
    {
      "name": "K-Ryan Hinds"
    },
    {
      "name": "Anjasha Gangopadhyay"
    },
    {
      "name": "Jonay Isaí Gonzalez-Hernandez"
    },
    {
      "name": "Assaf Horesh"
    },
    {
      "name": "Giorgos Leloudas"
    },
    {
      "name": "Eliana Palazzi"
    },
    {
      "name": "Daniel A. Perley"
    },
    {
      "name": "Frédérick Poidevin"
    },
    {
      "name": "Ramon Sanfeliu"
    },
    {
      "name": "Jacob L. Wise"
    },
    {
      "name": "Erez A. Zimmerman"
    },
    {
      "name": "Alice Cai"
    },
    {
      "name": "Joahan Jaimes"
    },
    {
      "name": "Ting-Wan Chen"
    },
    {
      "name": "Michael W. Coughlin"
    },
    {
      "name": "Richard Dekany"
    },
    {
      "name": "Ori D. Fox"
    },
    {
      "name": "Christoffer Fremling"
    },
    {
      "name": "Matthew J. Graham"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/85tntdb4krx56.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.27312",
  "fulltext_url": null,
  "id": "85tntdb4krx56",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.27312",
  "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.HE"
    ],
    [
      "arxiv",
      "astro-ph.SR"
    ],
    [
      "openalex",
      "3103|Gamma-ray bursts and supernovae"
    ]
  ],
  "openalex": "W7223158510",
  "pdf_url": "https://arxiv.org/pdf/2610.27312",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-19",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/85tntdb4krx56.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:04Z",
      "native_id": "2610.27312",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.27312"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.SR",
      "subfield": "stellar"
    }
  ],
  "title": "SN 2023iop: An Extreme 1987A-like Supernova and the Death of Very Massive Stars",
  "title_text": "SN 2023iop: An Extreme 1987A-like Supernova and the Death of Very Massive Stars",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:04Z",
  "url": "https://research.draconitic.com/paper/85tntdb4krx56",
  "venue": "arXiv",
  "versions": []
}