{
  "abstract": "We construct and characterize a sample of 146 little red dots (LRDs) across ${2.0{\\lt} z{\\lt} 9.3}$, selecting all sources with v-shaped ultraviolet (UV)–optical continua from James Webb Space Telescope (JWST) NIRSpec/PRISM spectra and compact morphologies in NIRCam/F444W imaging. We show that LRD continuum spectra are well described by modified blackbodies across $\\sim 0.4-1.0\\, \\rm{\\mu m}$, with typical $T\\sim 5000\\,$ K ($\\lambda _{\\rm peak}\\sim 0.65\\, \\rm{\\mu m}$) across 2 dex in luminosity, and a tail toward $T\\sim 2000\\,$ K. LRDs therefore trace a locus in the Hertzsprung–Russell diagram that is analogous to stars on the Hayashi track, strongly supporting the picture that LRDs are active galactic nucleus (AGN) embedded in optically thick dense gas envelopes. Hotter LRDs with $\\lambda _{\\rm peak}\\lt 0.65\\, \\rm{\\mu m}$ typically have strong Balmer breaks, redder UV slopes, and high optical luminosities; other LRDs show weak or no Balmer breaks, and wide variety in $\\beta _{\\rm UV}$ and $L_{5100}$. Crucially, we demonstrate that the UV–optical continua are strongly linked to the H$\\alpha$, H$\\beta$, [O iii], and O i line properties. There is a tight linear relation between the H$\\alpha$ and optical continuum luminosities, as well as H$\\alpha$ and $\\rm {O\\, {\\small I} }_{\\ \\lambda 8446}$, indicating that Balmer, O i, and optical emission must primarily be powered by the same source. The Balmer decrement increases strongly toward higher $L_{\\rm H\\alpha }$, $L_{5100}$, and Balmer break strength, providing key evidence for luminosity-dependent effects of collisional (de-)excitation and resonant scattering in the gaseous envelopes. In contrast, we show that [O iii] emission likely originates from star-forming host galaxies, with strong variation in the AGN-to-host ratio among the LRD population. Our work presents an empirical description of the nature and structure of LRDs, defining a new benchmark for ongoing LRD model developments.",
  "abstract_shown": true,
  "affiliations": [
    "Center for Astrophysics | Harvard & Smithsonian , 60 Garden St., Cambridge, MA 02138 ,",
    "Max-Planck-Institut für Astronomie , Königstuhl 17, D-69117, Heidelberg ,",
    "MIT Kavli Institute for Astrophysics and Space Research , 70 Vassar Street, Cambridge, MA 02139 ,",
    "Department of Astrophysical Sciences, Princeton University , 4 Ivy Lane, Princeton, NJ 08544 ,",
    "Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Northwestern University , 1800 Sherman Ave, Evanston, IL 60201 ,",
    "Department of Astronomy & Astrophysics, The Pennsylvania State University , University Park, PA 16802 ,",
    "Institute for Computational & Data Sciences, The Pennsylvania State University , University Park, PA 16802 ,",
    "Institute for Gravitation and the Cosmos, The Pennsylvania State University , University Park, PA 16802 ,",
    "Institute of Science and Technology Austria (ISTA) , Am Campus 1, A-3400 Klosterneuburg ,",
    "Cosmic Dawn Center (DAWN), Niels Bohr Institute, University of Copenhagen , Jagtvej 128, København N, DK-2200 ,",
    "Department of Astronomy & Astrophysics, University of Chicago , 5640 S. Ellis Avenue, Chicago, IL 60637 ,",
    "Kavli Institute for Cosmological Physics, University of Chicago , Chicago, IL 60637 ,",
    "Department of Physics and Astronomy and PITT PACC, University of Pittsburgh , Pittsburgh, PA 15260 ,",
    "Leiden Observatory, Leiden University , PO Box 9513, NL-2300 RA Leiden ,",
    "Institute for Computational Cosmology, Department of Physics, Durham University , South Road, Durham DH1 3LE ,",
    "Cosmic Frontier Center, The University of Texas at Austin , Austin, TX 78712 ,",
    "Department of Astronomy, The University of Texas at Austin , 2515 Speedway, Stop C1400, Austin, TX 78712 ,",
    "Canadian Institute for Theoretical Astrophysics , University of Toronto, 60 St George St, Toronto, ON M5S 3H8 ,",
    "David A. Dunlap Department of Astronomy and Astrophysics, University of Toronto , 50 St George St, Toronto, ON M5S 3H4 ,",
    "Department of Physics , University of Toronto, 60 St George St, Toronto, ON M5S 3H8 ,",
    "Department of Astrophysics, University of Zurich , Zurich CH-8057 ,",
    "Center for Frontier Science, Chiba University , 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 ,",
    "Dunlap Institute for Astronomy and Astrophysics , 50 St. George Street, Toronto, ON M5S 3H4 ,",
    "Centre for Astrophysics and Supercomputing, Swinburne University of Technology , Melbourne, VIC 3122 ,",
    "Department of Astronomy, University of Geneva , Chemin Pegasi 51, CH-1290 Versoix ,",
    "Department of Astronomy, University of Wisconsin-Madison , 475 N. Charter St., Madison, WI 53706 ,",
    "Department for Astrophysical and Planetary Science, University of Colorado , Boulder, CO 80309 ,",
    "Astronomical Observatory Institute, Faculty of Physics and Astronomy, Adam Mickiewicz University , ul. Słoneczna 36, PL-60-286, Poznań ,",
    "California Institute of Technology , Pasadena, CA 91125 ,",
    "Sterrenkundig Observatorium, Universiteit Gent , Krijgslaan 281 S9, B-9000 Gent ,"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 37,
  "authors": [
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        1
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      "name": "Anna de Graaff",
      "orcid": "0000-0002-2380-9801"
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      "name": "Raphael E Hviding",
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      "name": "Pratika Dayal",
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      "name": "Robert Feldmann",
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      "name": "Yoshinobu Fudamoto",
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      "name": "Seiji Fujimoto",
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      "name": "Lukas J. Furtak",
      "orcid": "0000-0001-6278-032X"
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        23
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      "name": "Karl Glazebrook",
      "orcid": "0000-0002-3254-9044"
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      "name": "Rashmi Gottumukkala",
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      "name": "Kasper E Heintz",
      "orcid": "0000-0002-9389-7413"
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        16
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      "name": "Vasily Kokorev",
      "orcid": "0000-0002-5588-9156"
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      "affs": [
        23
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      "name": "Ivo Labbe",
      "orcid": "0000-0002-2057-5376"
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    {
      "affs": [
        25
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      "name": "Michael V Maseda",
      "orcid": "0000-0003-0695-4414"
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    {
      "affs": [
        25
      ],
      "name": "Ian McConachie",
      "orcid": "0000-0002-2446-8770"
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    {
      "affs": [
        23
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      "name": "Themiya Nanayakkara",
      "orcid": "0000-0003-2804-0648"
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        26
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      "name": "Erica Nelson",
      "orcid": "0000-0002-7524-374X"
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    {
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        27
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      "name": "Przemysław Nowaczyk",
      "orcid": "0000-0003-0771-8827"
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      "name": "Pascal A. Oesch",
      "orcid": "0000-0001-5851-6649"
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      "name": "Hans-Walter Rix",
      "orcid": "0000-0003-4996-9069"
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      "name": "David J. Setton",
      "orcid": "0000-0003-4075-7393"
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      "name": "Alberto Torralba",
      "orcid": "0000-0001-5586-6950"
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      "name": "Fabian Walter",
      "orcid": "0000-0003-4793-7880"
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      "name": "Bingjie Wang",
      "orcid": "0000-0001-9269-5046"
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      "name": "Andrea Weibel",
      "orcid": "0000-0001-8928-4465"
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      "name": "Arjen van der Wel",
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  "bibtex": "https://research.draconitic.com/paper/0x9jfevpe8thw.bib",
  "cited_by": 130,
  "doi": "10.1093/mnras/stag1567",
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  "id": "0x9jfevpe8thw",
  "issns": [
    "0035-8711",
    "1365-2966",
    "1365-8711"
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  "landing_url": "https://doi.org/10.1093/mnras/stag1567",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
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  "pdf_url": "https://academic.oup.com/mnras/advance-article-pdf/doi/10.1093/mnras/stag1567/70758423/stag1567.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-21",
  "publisher": "Oxford University Press",
  "ris": "https://research.draconitic.com/paper/0x9jfevpe8thw.ris",
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    {
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      "url": "https://doi.org/10.1093/mnras/stag1567"
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  "subjects": [
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      "field": "astronomy",
      "origin": "openalex:3103|Galaxies: Formation, Evolution, Phenomena",
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  ],
  "title": "Little red dots host black hole stars: a unified family of gas-reddened AGN revealed by JWST /NIRSpec spectroscopy",
  "title_text": "Little red dots host black hole stars: a unified family of gas-reddened AGN revealed by JWST /NIRSpec spectroscopy",
  "type": "peer-reviewed",
  "updated_at": "2026-11-07T13:20:44Z",
  "url": "https://research.draconitic.com/paper/0x9jfevpe8thw",
  "venue": "Monthly Notices of the Royal Astronomical Society",
  "versions": []
}