{
  "annotation_id": "439c893c-e272-49a6-9ce0-56a331de5042",
  "date_created": "2026-02-17T05:53:20.332000Z",
  "date_modified": "2026-02-17T05:53:20.332000Z",
  "file_hash": "8e87d851d104c8198e8f5fa5c5408a2cc431e7cbb89e6fd5a87e2ac3de00070e",
  "private": false,
  "record": {
    "abstract": "The young TOI-451 planetary system, aged 125 Myr, provides a unique opportunity to test theories of planetary internal structures and atmospheric mass loss through examination of its three transiting planets. We present an exhaustive photometric and spectroscopic follow-up to determine the orbital and physical properties of the system. We perform multidimensional Gaussian Process regression with the code pyaneti on spectroscopic time-series and NGTS/LCO light curves to disentangle the stellar and planetary signal in ESPRESSO radial velocities. We show how contemporaneous photometry serves as an activity indicator to inform RV modelling within a multidimensional Gaussian Processes framework. We argue that this can be exploited when spectroscopic observations are adversely affected by low signal-to-noise and/or poor sampling. We estimate the Doppler semi-amplitudes of Kb = 2.6(+1.1,-1.2) m/s, Kc = 1.2(+1.0,-0.8) m/s and Kd = 2.7 +/- 1.2 m/s. This translates into 2-sigma mass estimates for TOI-451 b and d of Mb = 4.7(+2.1,-2.2) Earth masses and Md = 10.2(+4.6,-4.5) Earth masses, as well as a mass upper limit for TOI-451 c of Mc \u003c 11.5 Earth masses. The derived planetary properties suggest that planets c and d contain significant hydrogen-rich envelopes. The inferred parameters of TOI-451 b are consistent with either a rocky world that still retains a small hydrogen envelope or a water world. These insights make the TOI-451 system an ideal laboratory for future follow-up studies aimed at measuring atmospheric compositions, detecting atmospheric mass-loss signatures, and further exploring planetary formation and evolution processes.",
    "arxiv_id": "2601.09438",
    "authors": [
      "Oscar Barrag\u00e1n",
      "Manuel Mallorqu\u00edn",
      "Jorge Fern\u00e1ndez-Fern\u00e1ndez",
      "Faith Hawthorn",
      "Alix V. Freckelton",
      "Marina Lafarga",
      "Michael Cretignier",
      "Yoshi N. E. Eschen",
      "Samuel Gill",
      "V\u00edctor J. S. B\u00e9jar",
      "Nicolas Lodieu",
      "Haochuan Yu",
      "Thomas G. Wilson",
      "David Anderson",
      "Ioannis Apergis",
      "Matthew Battley",
      "Edward M. Bryant",
      "P\u00eda Cort\u00e9s-Zuleta",
      "Edward Gillen",
      "James S. Jenkins",
      "Baptiste Klein",
      "James McCormac",
      "Annabella Meech",
      "Erik Meier-Vald\u00e9s",
      "Maximiliano Moyano",
      "Annelies Mortier",
      "Felipe Murgas",
      "Louise D. Nielsen",
      "Suman Saha",
      "Jos\u00e9 I. Vines",
      "Richard West",
      "Peter J. Wheatley",
      "Suzanne Aigrain"
    ],
    "categories": [
      "astro-ph.EP",
      "astro-ph.SR"
    ],
    "doi": "10.1093/mnras/stag087",
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "title": "Mass estimates of the young TOI-451 transiting planets: Multidimensional Gaussian Process on stellar spectroscopic and photometric signals",
    "url": "https://arxiv.org/abs/2601.09438",
    "version": "v1"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "1917f99a-05f5-403b-8494-815ed2c8b229",
    "id": "arXiv Dataset",
    "type": "Model",
    "variant": "snapshot-2026-01-17",
    "version": "0.1.0"
  },
  "user_id": 1000002
}