{
  "abstract": "Hot Jupiters are typically thought to be \"lonely\", but a small and growing subset of them have been found to have nearby planets in the same system. We present the discovery of a new member of this class of systems, TOI-3686. TOI-3686 c is a hot Jupiter with $P_\\mathrm{orb} = 5.078$ days detected by NASA's TESS mission that shows peak-to-peak transit timing variations (TTVs) of 40 minutes, amongst the largest ever observed for a hot Jupiter. A subsequent search of the TESS data revealed the transits of a second planet, TOI-3686 b, a sub-Neptune with $P_\\mathrm{orb} = 2.54$~days and peak-to-peak TTVs of 10 hours, $\\sim 16\\%$ of its orbital period. We characterized the system through photodynamical modeling of photometry from TESS and ground-based facilities, as well as radial velocity measurements from the NEID and MAROON-X spectrographs. We find that the two planets in the TOI-3686 system are deep in a 2:1 mean-motion resonance, making this the only hot Jupiter system currently known to be in a truly resonant configuration, which may be related to its $\\lesssim1$~Gyr system age. Systems like TOI-3686 likely formed through a dynamically quiescent pathway and were captured into resonance after migration through a disk, and may represent the high-mass end of processes that occur in compact systems of smaller planets.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.28533",
  "author_total": 53,
  "authors": [
    {
      "name": "Samuel W. Yee"
    },
    {
      "name": "Tarisai Dziire"
    },
    {
      "name": "Karen A. Collins"
    },
    {
      "name": "Luke G. Bouma"
    },
    {
      "name": "Daniel Tamayo"
    },
    {
      "name": "Erik A. Petigura"
    },
    {
      "name": "Allyson Bieryla"
    },
    {
      "name": "David W. Latham"
    },
    {
      "name": "Samuel N. Quinn"
    },
    {
      "name": "Joshua N. Winn"
    },
    {
      "name": "Joel D. Hartman"
    },
    {
      "name": "Boris S. Safonov"
    },
    {
      "name": "Raquel Forés-Toribio"
    },
    {
      "name": "Jose A. Muñoz"
    },
    {
      "name": "Khalid Barkaoui"
    },
    {
      "name": "Richard P. Schwarz"
    },
    {
      "name": "Francis P. Wilkin"
    },
    {
      "name": "Paul Benni"
    },
    {
      "name": "Krzysztof Bernacki"
    },
    {
      "name": "Nikita Chazov"
    },
    {
      "name": "Eric G. Hintz"
    },
    {
      "name": "Glauk Hizmo"
    },
    {
      "name": "George Iwaszek"
    },
    {
      "name": "Adam Popowicz"
    },
    {
      "name": "Manfred Raetz"
    },
    {
      "name": "Miquel Serra-Ricart"
    },
    {
      "name": "Gregor Srdoc"
    },
    {
      "name": "Denise C. Stephens"
    },
    {
      "name": "Joseph Williams"
    },
    {
      "name": "Valerio Bozza"
    },
    {
      "name": "Otabek Burkhonov"
    },
    {
      "name": "Roger Dymock"
    },
    {
      "name": "Salokhiddin Sh. Ergashev"
    },
    {
      "name": "Karen Fischer"
    },
    {
      "name": "Cristilyn N. Gardner-Watkins"
    },
    {
      "name": "Ferran Grau Horta"
    },
    {
      "name": "Adam Lark"
    },
    {
      "name": "Katherine Linnenkohl"
    },
    {
      "name": "Ken Mason"
    },
    {
      "name": "Edward J. Michaels"
    },
    {
      "name": "Owen A. J. Mitchem"
    },
    {
      "name": "Seth M. Pritchard"
    },
    {
      "name": "Lauren A. Sgro"
    },
    {
      "name": "Neil B. Thomas"
    },
    {
      "name": "Siegfried Vanaverbeke"
    },
    {
      "name": "Pieter Vuylsteke"
    },
    {
      "name": "Jeroen Audenaert"
    },
    {
      "name": "Keith Horne"
    },
    {
      "name": "Felipe Murgas"
    },
    {
      "name": "Emma Nabbie"
    },
    {
      "name": "Enric Palle"
    },
    {
      "name": "Ramotholo Sefako"
    },
    {
      "name": "Avi Shporer"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5zmkmvjwnstz8.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.28533",
  "fulltext_url": null,
  "id": "5zmkmvjwnstz8",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.28533",
  "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",
      "3103|Stellar, planetary, and galactic studies"
    ]
  ],
  "openalex": "W7223137856",
  "pdf_url": "https://arxiv.org/pdf/2610.28533",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-20",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5zmkmvjwnstz8.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:04Z",
      "native_id": "2610.28533",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.28533"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.EP",
      "subfield": "planetary"
    }
  ],
  "title": "TOI-3686: A Hot Jupiter and Sub-Neptune In A 2:1 Mean-Motion Resonance",
  "title_text": "TOI-3686: A Hot Jupiter and Sub-Neptune In A 2:1 Mean-Motion Resonance",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:04Z",
  "url": "https://research.draconitic.com/paper/5zmkmvjwnstz8",
  "venue": "arXiv",
  "versions": []
}