{
  "abstract": "LP 890-9, also known as SPECULOOS-2 and TOI-4306, is a nearby late-M dwarf hosting two confirmed transiting rocky exoplanets. We analyze 20 JWST/NIRSpec PRISM transits of LP 890-9b and LP 890-9c obtained as part of GO program 7073 and detect statistically significant transit timing variations (TTVs), with peak-to-peak amplitudes of ~17 s and ~35 s, respectively. Using analytic linear TTV theory, we find that the known two-planet configuration cannot reproduce the measured TTV amplitudes or super-period, whereas three-planet models provide substantially better fits. The best-fit configuration places the candidate third planet, LP 890-9d, between planets b and c, with an orbital period of ~4.4 days; however, the current data do not uniquely determine its orbital architecture, and periods spanning 4.0-6.9 days remain plausible. TESS is insensitive to transits of LP 890-9d and we find no evidence for the candidate in JWST observations, although the phase coverage (ranging from ~50% to ~80%) depends strongly on the candidate orbital period. Additional high-precision transit observations of LP 890-9b and LP 890-9c are needed to refine their TTV solutions and further constrain the orbital properties of the third planet.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.05312",
  "author_total": 13,
  "authors": [
    {
      "name": "Kevin B. Stevenson"
    },
    {
      "name": "Guangwei Fu"
    },
    {
      "name": "Kristin S. Sotzen"
    },
    {
      "name": "E. M. May"
    },
    {
      "name": "Larissa Palethorpe"
    },
    {
      "name": "Jacob Lustig-Yaeger"
    },
    {
      "name": "Ted M. Johnson"
    },
    {
      "name": "Eric Agol"
    },
    {
      "name": "Katherine A. Bennett"
    },
    {
      "name": "Carlos Gascón"
    },
    {
      "name": "David K. Sing"
    },
    {
      "name": "Jeff A. Valenti"
    },
    {
      "name": "Hannah R. Wakeford"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/d0yvgb3wk7nkt.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.05312",
  "fulltext_url": null,
  "id": "d0yvgb3wk7nkt",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.05312",
  "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",
      "3103|Stellar, planetary, and galactic studies"
    ]
  ],
  "openalex": "W7211885545",
  "pdf_url": "https://arxiv.org/pdf/2609.05312",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/d0yvgb3wk7nkt.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:14Z",
      "native_id": "2609.05312",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.05312"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.EP",
      "subfield": "planetary"
    }
  ],
  "title": "Evidence for LP 890-9d via Transit Timing Variations",
  "title_text": "Evidence for LP 890-9d via Transit Timing Variations",
  "type": "preprint",
  "updated_at": "2026-10-30T12:19:14Z",
  "url": "https://research.draconitic.com/paper/d0yvgb3wk7nkt",
  "venue": "arXiv",
  "versions": []
}