{
  "abstract": "We present well-sampled multi-band imaging and low- to medium-resolution spectroscopic observations of the early-discovered Type~II supernova (SN)~2025dys. The photometric evolution exhibits a rise time of $\\sim$\\,18 days ($r$ band) and a rapid decline transitioning to the radioactive decay tail at $\\sim$\\,70 days. SN~2025dys is among the high-luminosity events with a peak pseudo-bolometric luminosity of $L_{\\rm opt}=8.57\\times10^{42}\\,\\mathrm{erg\\,s^{-1}}$. Early X-ray emission was identified, displaying a luminosity of $7.55\\times10^{40}\\,\\mathrm{erg\\,s^{-1}}$. The observational investigation points to a dense, hydrogen-rich circumstellar medium with a mass of $M_{\\rm CSM}\\approx0.5$--$0.7\\,\\mathrm{M_\\odot}$, suggesting a partially stripped, hydrogen-poor inner ejecta with a relatively low mass of $M_{\\rm ej}\\approx2.5\\,\\mathrm{M_\\odot}$. The explosion possessed a kinetic energy of $E_{\\rm k}\\approx0.3\\text{--}0.5$~foe and yielded a synthesized nickel mass of $M_{\\rm Ni}\\approx0.042_{-0.011}^{+0.012}\\,\\mathrm{M_\\odot}$. These physical parameters indicate an extreme mass-loss episode before the explosion, characterized by a high mass-loss rate of $\\dot{M} \\gtrsim 0.01\\,\\mathrm{M_\\odot\\,yr^{-1}}$. SN~2025dys represents a stripped progenitor, intrinsically resembling a Type~IIb or even a Type~Ib SN, that exploded within a dense, hydrogen-rich circumstellar environment.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.41729",
  "author_total": 28,
  "authors": [
    {
      "name": "Jiewei Zhao"
    },
    {
      "name": "Brajesh Kumar"
    },
    {
      "name": "Gitika Rameshan"
    },
    {
      "name": "Devendra K. Sahu"
    },
    {
      "name": "Bin-Bin Zhang"
    },
    {
      "name": "Kamil Nadaf"
    },
    {
      "name": "Guowang Du"
    },
    {
      "name": "Wenyu Li"
    },
    {
      "name": "Zehui Peng"
    },
    {
      "name": "Jinghua Zhang"
    },
    {
      "name": "Shiyan Zhong"
    },
    {
      "name": "Xiangkun Liu"
    },
    {
      "name": "Avinash Singh"
    },
    {
      "name": "Xinlei Chen"
    },
    {
      "name": "Yuan Fang"
    },
    {
      "name": "Yu Pan"
    },
    {
      "name": "Xingzhu Zou"
    },
    {
      "name": "Hrishav Das"
    },
    {
      "name": "Mridweeka Singh"
    },
    {
      "name": "Amrit Dutta"
    },
    {
      "name": "G. C. Anupama"
    },
    {
      "name": "Xueling Du"
    },
    {
      "name": "Yang Yang"
    },
    {
      "name": "Kaushik Chatterjee"
    },
    {
      "name": "Tao Wang"
    },
    {
      "name": "Xufeng Zhu"
    },
    {
      "name": "Yuan-Pei Yang"
    },
    {
      "name": "Xiaowei Liu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1pj36y3xrjkf5.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.41729",
  "fulltext_url": null,
  "id": "1pj36y3xrjkf5",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.41729",
  "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": null,
  "pdf_url": "https://arxiv.org/pdf/2610.41729",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/1pj36y3xrjkf5.ris",
  "sources": [
    {
      "first_seen": "2026-11-02T12:21:15Z",
      "native_id": "2610.41729",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.41729"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.SR",
      "subfield": "stellar"
    }
  ],
  "title": "SN 2025dys: A luminous supernova explosion from a partially stripped helium star",
  "title_text": "SN 2025dys: A luminous supernova explosion from a partially stripped helium star",
  "type": "preprint",
  "updated_at": "2026-11-04T15:20:51Z",
  "url": "https://research.draconitic.com/paper/1pj36y3xrjkf5",
  "venue": "arXiv",
  "versions": []
}