{
  "id": "2203.01554",
  "version": "v1",
  "published": "2022-03-03T08:07:31.000Z",
  "updated": "2022-03-03T08:07:31.000Z",
  "title": "The exoplanetary magnetosphere extension in Sun-like stars based on the solar wind - solar UV relation",
  "authors": [
    "Raffaele Reda",
    "Luca Giovannelli",
    "Tommaso Alberti",
    "Francesco Berrilli",
    "Luca Bertello",
    "Dario Del Moro",
    "Maria Pia Di Mauro",
    "Piermarco Giobbi",
    "Valentina Penza"
  ],
  "comment": "9 pages, 6 figures",
  "categories": [
    "astro-ph.SR",
    "astro-ph.EP",
    "physics.space-ph"
  ],
  "abstract": "Earth's magnetosphere extension is controlled by solar activity level via solar wind properties. Understanding such a relation in the Solar System is useful to predict the condition of exoplanetary magnetosphere near Sun-like stars. We use measurements of a chromospheric proxy, the Ca II K index, and solar wind OMNI parameters to connect the solar activity variations on the decennial time scales to solar wind properties. The dataset span over the time interval 1965-2021, which almost entirely covers the last 5 solar cycles. Using both cross-correlation and mutual information analysis, a 3.2-year lag of the solar wind speed with respect to the Ca II K index is found. Analogously, a 3.6-year lag is found with respect to the dynamic pressure. A correlation between the solar wind dynamic pressure and the solar UV emission is therefore found and used to derive the Earth's magnetopause standoff distance. Moreover, the advantage of using a chromospheric proxy, such as the Ca II K index, opens the possibility to extend the relation found for the Sun to Sun-like stars, by linking stellar variability to stellar wind properties. The model is applied to a sample of Sun-like stars as a case study, where we assume the presence of an Earth-like exoplanet at 1 AU. Finally, we compare our results with previous estimates of the magnetosphere extension for the same set of sun-like stars.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-03-03T08:07:31.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "sun-like stars",
      "exoplanetary magnetosphere extension",
      "solar uv relation",
      "solar wind properties",
      "chromospheric proxy"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 9,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}