{
  "abstract": "Binary stars are the progenitors of exotic objects, such as supernovae and gravitational-wave sources. However, some systems merge earlier, when the primary expands into a giant star at the end of its lifetime on the main sequence and causes its companion to spiral in. TYC 4144-329-2 is a candidate postmerger first-ascent giant star with a circumstellar disk seen in the infrared (IR). We detect weak X-ray and far-ultraviolet (FUV) emission from TYC 4144-329-2, which we interpret as a signature of weak coronal activity. We also find variability in H α line profiles and in the optical light curves, and we suggest an intermediate geometry where the line of sight passes through the upper layers of a flared disk with a time-variable column density. While the X-rays must be coronal, the H α line profiles point to ongoing and variable accretion. We suggest that TYC 4144-329-2’s merger was more recent than those of other stars in this class and that it did not yet have time to develop a deep convection zone. If this scenario holds, TYC 4144-329-2 would be a unique probe of the earliest stages in the evolution of postmerger systems.",
  "abstract_shown": true,
  "affiliations": [
    "MIT Kavli Institute for Astrophysics and Space Research",
    "University of California San Diego",
    "University of California",
    "University of Rochester",
    "University of Florida",
    "Christian-Albrechts-Universität zu Kiel"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "H. M. Günther",
      "orcid": "0000-0003-4243-2840"
    },
    {
      "affs": [
        1
      ],
      "name": "C. Melis",
      "orcid": "0000-0001-9834-7579"
    },
    {
      "affs": [
        2
      ],
      "name": "K. J. Shen",
      "orcid": "0000-0002-9632-6106"
    },
    {
      "affs": [
        3
      ],
      "name": "Eric G. Blackman",
      "orcid": "0000-0002-9405-8435"
    },
    {
      "affs": [
        4
      ],
      "name": "K. Hoadley",
      "orcid": "0000-0002-8636-3309"
    },
    {
      "affs": [
        5
      ],
      "name": "P. C. Schneider",
      "orcid": "0000-0002-5094-2245"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7vhn2s5g3t6v8.bib",
  "cited_by": 0,
  "doi": "10.3847/1538-4357/aea619",
  "fulltext_url": null,
  "id": "7vhn2s5g3t6v8",
  "issns": [
    "0004-637X",
    "1538-4357"
  ],
  "landing_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea619",
  "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|Stellar, planetary, and galactic studies"
    ]
  ],
  "openalex": "W7213280515",
  "pdf_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea619/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-07",
  "publisher": "American Astronomical Society",
  "ris": "https://research.draconitic.com/paper/7vhn2s5g3t6v8.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:11Z",
      "native_id": "10.3847/1538-4357/aea619",
      "source": "crossref",
      "url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea619"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Stellar, planetary, and galactic studies",
      "subfield": "stellar"
    }
  ],
  "title": "Stellar Activity in a Postmerger Giant Star",
  "title_text": "Stellar Activity in a Postmerger Giant Star",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:11Z",
  "url": "https://research.draconitic.com/paper/7vhn2s5g3t6v8",
  "venue": "The Astrophysical Journal",
  "versions": []
}