{
  "abstract": "The angle between stellar spin axis and planetary orbital plane can provide key insights into the formation and dynamical evolution of planetary systems. In particular, this measurement in multi-planet systems can be used to further discriminate between different competing migration scenarios. We present six transit observations of the sub-Neptune GJ3090 b obtained with NIRPS and HARPS. GJ3090 b is the inner planet of a confirmed multi-planet system orbiting an M dwarf (M2). Using high spectral resolution and high temporal cadence spectroscopic observations, we analyzed the Rossiter-McLaughlin (RM) effect induced by GJ3090 b to determine its orbital obliquity. Through the RM revolutions technique, we find that the planet is on a retrograde orbit with a derived 3D obliquity of $ψ= 136^{+24}_{-18}\\,\\mathrm{deg}$. We find no evidence of massive outer planetary or wide stellar binary companions, which disfavors scenarios involving gravitational perturbations from a massive body and instead points toward a primordial misalignment of the protoplanetary disk. Our results establish GJ3090 b as the first planet on a retrograde orbit discovered around an M dwarf and the first highly misaligned confirmed multi-planet system without a known massive companion. We further propose late secondary disk accretion around GJ3090, in which the disk is not expected to be aligned with the stellar spin axis, followed by disk-driven migration as the most likely mechanisms to explain the observed architecture. This work also illustrates the capability of the RM revolutions technique when applied to near-infrared data to probe orbital architectures of the smallest planets around M dwarfs that have remained mostly inaccessible.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": "Journal reference: A&A, Volume 713, September 2026, L15",
  "arxiv": "2609.24870",
  "author_total": 60,
  "authors": [
    {
      "name": "Y. Carteret"
    },
    {
      "name": "V. Bourrier"
    },
    {
      "name": "L. Parc"
    },
    {
      "name": "A. Winter"
    },
    {
      "name": "R. Allart"
    },
    {
      "name": "I. de Castro Leão"
    },
    {
      "name": "F. Bouchy"
    },
    {
      "name": "V. M. Passegger"
    },
    {
      "name": "C. Cadieux"
    },
    {
      "name": "P. Lamontagne"
    },
    {
      "name": "É. Artigau"
    },
    {
      "name": "F. Baron"
    },
    {
      "name": "S. C. C. Barros"
    },
    {
      "name": "B. Benneke"
    },
    {
      "name": "X. Bonfils"
    },
    {
      "name": "M. Bryan"
    },
    {
      "name": "B. L. Canto Martins"
    },
    {
      "name": "R. Cloutier"
    },
    {
      "name": "E. Cristo"
    },
    {
      "name": "J. Gagné"
    },
    {
      "name": "N. J. Cook"
    },
    {
      "name": "N. B. Cowan"
    },
    {
      "name": "J. R. De Medeiros"
    },
    {
      "name": "X. Delfosse"
    },
    {
      "name": "R. Doyon"
    },
    {
      "name": "X. Dumusque"
    },
    {
      "name": "D. Ehrenreich"
    },
    {
      "name": "J. I. González Hernández"
    },
    {
      "name": "D. Lafrenière"
    },
    {
      "name": "C. Lovis"
    },
    {
      "name": "L. Malo"
    },
    {
      "name": "C. Melo"
    },
    {
      "name": "L. Mignon"
    },
    {
      "name": "C. Mordasini"
    },
    {
      "name": "F. Pepe"
    },
    {
      "name": "R. Rebolo"
    },
    {
      "name": "J. Rowe"
    },
    {
      "name": "N. C. Santos"
    },
    {
      "name": "D. Ségransan"
    },
    {
      "name": "A. Suárez Mascareño"
    },
    {
      "name": "S. Udry"
    },
    {
      "name": "D. Valencia"
    },
    {
      "name": "G. Wade"
    },
    {
      "name": "K. Al Moulla"
    },
    {
      "name": "R. G. de Souza Barros de Amorim"
    },
    {
      "name": "L. Dang"
    },
    {
      "name": "E. Deibert"
    },
    {
      "name": "D. O. Fontinele"
    },
    {
      "name": "T. Forveille"
    },
    {
      "name": "Y. G. C. Frensch"
    },
    {
      "name": "R. de Lima Gomes"
    },
    {
      "name": "D. Mounzer"
    },
    {
      "name": "S. Pelletier"
    },
    {
      "name": "R. Rosener"
    },
    {
      "name": "B. N. Skinner"
    },
    {
      "name": "A. Srivastava"
    },
    {
      "name": "A. K. Stefanov"
    },
    {
      "name": "V. Vaulato"
    },
    {
      "name": "J. P. Wardenier"
    },
    {
      "name": "D. Weisserman"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ay82t9p649nas.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.24870",
  "fulltext_url": null,
  "id": "ay82t9p649nas",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.24870",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.EP"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2609.24870",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-21",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ay82t9p649nas.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:23:19Z",
      "native_id": "2609.24870",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.24870"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.EP",
      "subfield": "planetary"
    }
  ],
  "title": "Upside down: GJ3090 b the first retrograde exoplanet around an M dwarf detected with NIRPS",
  "title_text": "Upside down: GJ3090 b the first retrograde exoplanet around an M dwarf detected with NIRPS",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:19Z",
  "url": "https://research.draconitic.com/paper/ay82t9p649nas",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1051/0004-6361/202661989",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}