{
  "id": "1806.00136",
  "version": "v1",
  "published": "2018-05-31T23:31:00.000Z",
  "updated": "2018-05-31T23:31:00.000Z",
  "title": "Signatures of magnetic activity in the seismic data of solar-type stars observed by Kepler",
  "authors": [
    "A. R. G. Santos",
    "T. L. Campante",
    "W. J. Chaplin",
    "M. S. Cunha",
    "M. N. Lund",
    "R. Kiefer",
    "D. Salabert",
    "R. A. Garcia",
    "G. R. Davies",
    "Y Elsworth",
    "R. Howe"
  ],
  "comment": "Accepted for publication in ApJS, 19(+86) pages, 11(+89) figures, 2(+87) tables",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "In the Sun, the frequencies of the acoustic modes are observed to vary in phase with the magnetic activity level. These frequency variations are expected to be common in solar-type stars and contain information about the activity-related changes that take place in their interiors. The unprecedented duration of Kepler photometric time-series provides a unique opportunity to detect and characterize stellar magnetic cycles through asteroseismology. In this work, we analyze a sample of 87 solar-type stars, measuring their temporal frequency shifts over segments of length 90 days. For each segment, the individual frequencies are obtained through a Bayesian peak-bagging tool. The mean frequency shifts are then computed and compared with: 1) those obtained from a cross-correlation method; 2) the variation in the mode heights; 3) a photometric activity proxy; and 4) the characteristic timescale of the granulation. For each star and 90-d sub-series, we provide mean frequency shifts, mode heights, and characteristic timescales of the granulation. Interestingly, more than 60% of the stars show evidence for (quasi-)periodic variations in the frequency shifts. In the majority of the cases, these variations are accompanied by variations in other activity proxies. About 20% of the stars show mode frequencies and heights varying approximately in phase, in opposition to what is observed for the Sun.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-05-31T23:31:00.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "solar-type stars",
      "magnetic activity",
      "seismic data",
      "mean frequency shifts",
      "signatures"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}