{
  "abstract": "Luminous red novae (LRNe) are potential signatures of common envelope evolution (CEE), a critical yet poorly understood phase in compact-binary formation. AT2025abao, an LRN in the Andromeda galaxy, originated from an asymptotic giant branch (AGB) progenitor and exhibited a prolonged pre-outburst transient. Lacking direct constraints on the companion, however, the system’s evolutionary fate remains unclear. Here, we unravel the binary nature of AT2025abao by modeling its complete evolution, from precursor to final outcome. We show that the 8 yr infrared precursor arises from a ~ 1 . 4 − 0.3 + 0.2 M ⊙ main-sequence companion inspiralling through the wind of a ∼6.9 M ⊙ AGB star. As CEE commences, the companion plunges into the envelope and launches a shock. Radiation hydrodynamic modeling of this outburst constrains the total ejecta mass to ∼0.92 M ⊙ and energy to ∼1.25 × 10 ⁴⁷ erg, revealing that only ∼0.57 M ⊙ becomes unbound. Subsequent radiative transfer simulations successfully reproduce the evolving spectral energy distribution. Crucially, our models indicate the main-sequence companion and AGB core survive in an eccentric orbit without merging at least 400 days after CEE onset. AT2025abao may therefore be the first observed CEE event caught forming a close compact binary, bridging a long-standing observational gap in compact-binary formation.",
  "abstract_shown": true,
  "affiliations": [
    "Tsinghua University",
    "Chinese Academy of Sciences",
    "Chinese Academy of Sciences (CAS)",
    "INAF—Osservatorio Astronomico di Padova",
    "University of Chinese Academy of Sciences",
    "University of Science and Technology of China",
    "Guizhou University",
    "Deep Space Exploration Laboratory",
    "National Institutes of Natural Sciences"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 12,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Zhuo 卓 Chen 陈",
      "orcid": "0000-0001-7420-9606"
    },
    {
      "affs": [
        1
      ],
      "name": "Yingzhen 英朕 Cui 崔",
      "orcid": "0000-0002-0029-8682"
    },
    {
      "affs": [
        0
      ],
      "name": "Tianshu 天枢 Wu 吴",
      "orcid": "0009-0008-1033-5476"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Yongzhi 永志 Cai 蔡",
      "orcid": "0000-0002-7714-493X"
    },
    {
      "affs": [
        2,
        1,
        4
      ],
      "name": "Hongwei 宏伟 Ge 葛",
      "orcid": "0000-0002-6398-0195"
    },
    {
      "affs": [
        3
      ],
      "name": "Andrea Reguitti",
      "orcid": "0000-0003-4254-2724"
    },
    {
      "affs": [
        5
      ],
      "name": "Minxuan Cai",
      "orcid": "0000-0003-4721-6477"
    },
    {
      "affs": [
        5,
        6,
        7
      ],
      "name": "Lulu 璐璐 Fan 范",
      "orcid": "0000-0003-4200-4432"
    },
    {
      "affs": [
        5,
        8
      ],
      "name": "Ji-An 继安 Jiang 姜",
      "orcid": "0000-0002-9092-0593"
    },
    {
      "affs": [
        5
      ],
      "name": "Tinggui 挺贵 Wang 王",
      "orcid": "0000-0002-1517-6792"
    },
    {
      "affs": [
        5
      ],
      "name": "Zelin 则林 Xu 徐",
      "orcid": "0009-0009-5238-2059"
    },
    {
      "affs": [
        5
      ],
      "name": "Jie 杰 Lin 林",
      "orcid": "0000-0003-3965-6931"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0122k8ww4tncb.bib",
  "cited_by": 0,
  "doi": "10.3847/2041-8213/aeb126",
  "fulltext_url": null,
  "id": "0122k8ww4tncb",
  "issns": [
    "2041-8205",
    "2041-8213"
  ],
  "landing_url": "https://iopscience.iop.org/article/10.3847/2041-8213/aeb126",
  "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": [
    [
      "openalex",
      "3103|Gamma-ray bursts and supernovae"
    ]
  ],
  "openalex": "W7223415276",
  "pdf_url": "https://iopscience.iop.org/article/10.3847/2041-8213/aeb126/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-23",
  "publisher": "American Astronomical Society",
  "ris": "https://research.draconitic.com/paper/0122k8ww4tncb.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:13Z",
      "native_id": "10.3847/2041-8213/aeb126",
      "source": "crossref",
      "url": "https://iopscience.iop.org/article/10.3847/2041-8213/aeb126"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Gamma-ray bursts and supernovae",
      "subfield": "high-energy-astrophysics"
    }
  ],
  "title": "Unravelling the Nature of AT2025abao: From Precursor to Final Fate",
  "title_text": "Unravelling the Nature of AT2025abao: From Precursor to Final Fate",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:13Z",
  "url": "https://research.draconitic.com/paper/0122k8ww4tncb",
  "venue": "The Astrophysical Journal Letters",
  "versions": []
}