{
  "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 (R$_\\mathrm{p}$$\\sim$1.4 R$_{\\mathrm{J}}$), hot Jupiter (T$\\sim$1500$ \\mathrm{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$) and stellar rotational velocity ($v\\sin{i_\\star}$). Atmospheric signals were searched using high-resolution spectroscopy, both with cross-correlation and single-line analyses, targeting key atomic and molecular species (e.g. \\ion{He}{I}, H$α$, \\ion{Na}{I}, H$_2$O, CO). We find a well-aligned orbit ($λ$ = 2.7$\\pm$1.1$^\\circ$) and $v\\sin{i_\\star}$ = 4.5$\\pm$0.1 km s$^{-1}$, improving upon previous constraints. No significant atmospheric absorption is detected in either VIS or NIR data. Injection-and-recovery tests exclude an isothermal atmosphere with metallicity [M/H]$\\lesssim$10$\\times$[M/H]$_\\odot$ and simultaneously a grey cloud top pressure P$_{\\rm cloud}\\gtrsim10$ 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": [],
  "article_type": null,
  "arxiv": "2610.12677",
  "author_total": 20,
  "authors": [
    {
      "name": "D. Sicilia"
    },
    {
      "name": "M. Basilicata"
    },
    {
      "name": "G. Guilluy"
    },
    {
      "name": "G. Scandariato"
    },
    {
      "name": "F. Borsa"
    },
    {
      "name": "C. Di Maio"
    },
    {
      "name": "M. Brogi"
    },
    {
      "name": "A. Chiavassa"
    },
    {
      "name": "L. Fossati"
    },
    {
      "name": "F. Amadori"
    },
    {
      "name": "P. Giacobbe"
    },
    {
      "name": "A. S. Bonomo"
    },
    {
      "name": "A. Sozzetti"
    },
    {
      "name": "L. Mancini"
    },
    {
      "name": "G. Andreuzzi"
    },
    {
      "name": "S. Colombo"
    },
    {
      "name": "V. Fardella"
    },
    {
      "name": "A. Ghedina"
    },
    {
      "name": "G. Mantovan"
    },
    {
      "name": "G. Piccinini"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/fgapa10zgr1gy.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.12677",
  "fulltext_url": null,
  "id": "fgapa10zgr1gy",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.12677",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.EP"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2610.12677",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-08",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/fgapa10zgr1gy.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:28:36Z",
      "native_id": "2610.12677",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.12677"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.EP",
      "subfield": "planetary"
    }
  ],
  "title": "The GAPS programme at TNG LXXXII. The first atmospheric investigation of the gas giant WASP-13b at high resolution with GIARPS",
  "title_text": "The GAPS programme at TNG LXXXII. The first atmospheric investigation of the gas giant WASP-13b at high resolution with GIARPS",
  "type": "preprint",
  "updated_at": "2026-10-30T12:28:36Z",
  "url": "https://research.draconitic.com/paper/fgapa10zgr1gy",
  "venue": "arXiv",
  "versions": []
}