{
  "abstract": "Low-density transiting gas giant exoplanets are key benchmarks for atmospheric studies. Despite their large-scale heights, many of them remain poorly characterised. We present the first atmospheric investigation at high-resolution of the inflated (Rp~1.4 RJ), hot Jupiter (T~1500 K) WASP-13 b aiming at constraining its atmospheric composition and refine its orbital geometry. We analysed four transits observed with GIARPS at the TNG. Updated stellar and planetary parameters were re-derived from the most precise literature values, and a new Rossiter-McLaughlin analysis was performed to measure the projected spin-orbit angle (λ) and stellar rotational velocity (vsin i⋆). Atmospheric signals were searched using high-resolution spectroscopy, both with cross-correlation and single-line analyses, targeting key atomic and molecular species (e.g. He i, Hα, Na i, H2O, CO). We find a well-aligned orbit (λ = 2.7±1.1○) and vsin i⋆ = 4.5±0.1 km s−1, improving upon previous constraints. No significant atmospheric absorption is detected in either VIS or NIR data. Injection-and-recovery tests exclude an isothermal atmosphere with metallicity [M/H]≲ 10 ×[M/H]⊙ and simultaneously a grey cloud top pressure Pcloud ≳ 10 mbar, under the assumption of chemical equilibrium. WASP-13 b appears to belong to the class of low-density hot Jupiters with weak or featureless transmission spectra, most likely shaped by the presence of high-altitude clouds. Although a highly metal-enriched atmosphere cannot be fully excluded, current evidence disfavours this scenario. Further observations with next-generation facilities will be essential to characterise the atmospheric properties of this challenging target.",
  "abstract_shown": true,
  "affiliations": [
    "INAF – Osservatorio Astrofisico di Catania , Via S. Sofia 78, 95123 Catania ,",
    "INAF – Osservatorio Astronomico di Brera , Via E. Bianchi 46, 23807 Merate (LC) ,",
    "INAF – Osservatorio Astrofisico di Torino , Via Osservatorio 20, 10025 Pino Torinese ,",
    "INAF – Osservatorio Astronomico di Palermo , Piazza del Parlamento, 1, 90134 Palermo ,",
    "University of Turin Department of Physics, , Via Pietro Giuria 1, 10125 Torino ,",
    "Université Côte d’Azur , Observatoire de la Côte d’Azur, CNRS, Lagrange, CS 34229, Nice ,",
    "Space Research Institute, Austrian Academy of Sciences , Schmiedl- strasse 6, 8042 Graz ,",
    "University of Rome ”Tor Vergata” Department of Physics, , Via della Ricerca Scientifica 1, 00133 Roma ,",
    "Fundación Galileo Galilei - INAF , Rambla José Ana Fernandez Pérez 7, E-38712 Breña Baja, TF ,",
    "INAF – Osservatorio Astronomico di Roma , Via Frascati 33, I-00078 Monte Porzio Catone ,",
    "University of Palermo , Department of Physics and Chemistry ”Emilio Segré”, Via Archirafi 36, Palermo ,",
    "Centro di Ateneo di Studi e Attivitá Spaziali “G. Colombo” Universiá degli Studi di Padova , Via Venezia 15, 35131 Padova ,",
    "INAF – Osservatorio Astronomico di Padova , vicolo dell’Osservatorio 5, I-35122 Padova ,"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 20,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "D Sicilia",
      "orcid": "0000-0001-7851-5168"
    },
    {
      "affs": [
        1
      ],
      "name": "M Basilicata"
    },
    {
      "affs": [
        2
      ],
      "name": "G Guilluy"
    },
    {
      "affs": [
        0
      ],
      "name": "G Scandariato"
    },
    {
      "affs": [
        1
      ],
      "name": "F Borsa"
    },
    {
      "affs": [
        3
      ],
      "name": "C Di Maio"
    },
    {
      "affs": [
        4,
        2
      ],
      "name": "M Brogi"
    },
    {
      "affs": [
        5,
        2
      ],
      "name": "A Chiavassa"
    },
    {
      "affs": [
        6
      ],
      "name": "L Fossati"
    },
    {
      "affs": [
        2,
        4
      ],
      "name": "F Amadori"
    },
    {
      "affs": [
        2
      ],
      "name": "P Giacobbe"
    },
    {
      "affs": [
        2
      ],
      "name": "A S Bonomo"
    },
    {
      "affs": [
        2
      ],
      "name": "A Sozzetti"
    },
    {
      "affs": [
        7,
        2
      ],
      "name": "L Mancini",
      "orcid": "0000-0002-9428-8732"
    },
    {
      "affs": [
        8,
        9
      ],
      "name": "G Andreuzzi"
    },
    {
      "affs": [
        3
      ],
      "name": "S Colombo"
    },
    {
      "affs": [
        3,
        10
      ],
      "name": "V Fardella"
    },
    {
      "affs": [
        8
      ],
      "name": "A Ghedina"
    },
    {
      "affs": [
        11,
        12
      ],
      "name": "G Mantovan",
      "orcid": "0000-0002-6871-6131"
    },
    {
      "affs": [
        3,
        10
      ],
      "name": "G Piccinini",
      "orcid": "0009-0008-1256-8273"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/136y89tzv2nhf.bib",
  "cited_by": 0,
  "doi": "10.1093/mnras/stag1927",
  "fulltext_url": null,
  "id": "136y89tzv2nhf",
  "issns": [
    "0035-8711",
    "1365-2966"
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  "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"
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  "pdf_url": "https://academic.oup.com/mnras/advance-article-pdf/doi/10.1093/mnras/stag1927/71838588/stag1927.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-10",
  "publisher": "Oxford University Press (OUP)",
  "ris": "https://research.draconitic.com/paper/136y89tzv2nhf.ris",
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    {
      "first_seen": "2026-10-30T12:18:17Z",
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  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Stellar, planetary, and galactic studies",
      "subfield": "stellar"
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  ],
  "title": "The GAPS programme at TNG LXXXII. The first atmospheric investigation of the gas giant WASP-13 b at high resolution with GIARPS",
  "title_text": "The GAPS programme at TNG LXXXII. The first atmospheric investigation of the gas giant WASP-13 b at high resolution with GIARPS",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:17Z",
  "url": "https://research.draconitic.com/paper/136y89tzv2nhf",
  "venue": "Monthly Notices of the Royal Astronomical Society",
  "versions": []
}