{
  "id": "1805.09922",
  "version": "v1",
  "published": "2018-05-24T22:10:26.000Z",
  "updated": "2018-05-24T22:10:26.000Z",
  "title": "The K2 M67 Study: Establishing the Limits of Stellar Rotation Period Measurements in M67 with K2 Campaign 5 Data",
  "authors": [
    "Rebecca Esselstein",
    "Suzanne Aigrain",
    "Andrew Vanderburg",
    "Jeffrey C. Smith",
    "Soren Meibom",
    "Jennifer Van Saders",
    "Robert Mathieu"
  ],
  "comment": "55 pages (in current form), 22 figures, version accepted by ApJ but before final proofs",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "The open cluster M67 offers the unique opportunity to measure rotation periods for solar-age stars across a range of masses, potentially filling a critical gap in the understanding of angular momentum loss in older main sequence stars. The observation of M67 by NASA K2 Campaign 5 provided light curves with high enough precision to make this task possible, albeit challenging, as the pointing instability, 75d observation window, crowded field, and typically low-amplitude signals mean determining accurate rotation periods on the order of 25 - 30d is inherently difficult. Lingering, non-astrophysical signals with power at >25d found in a set of Campaign 5 A and F stars compounds the problem. To achieve a quantitative understanding of the best-case scenario limits for reliable period detection imposed by these inconveniences, we embarked on a comprehensive set of injection tests, injecting 120,000 sinusoidal signals with periods ranging from 5 to 35d and amplitudes from 0.05% to 3.0% into real Campaign 5 M67 light curves processed using two different pipelines. We attempted to recover the signals using a normalized version of the Lomb-Scargle periodogram and setting a detection threshold. We find that while the reliability of detected periods is high, the completeness (sensitivity) drops rapidly with increasing period and decreasing amplitude, maxing at 15% recovery rate for the solar case (i.e. 25d period, 0.1% amplitude). This study highlights the need for caution in determining M67 rotation periods from Campaign 5 data, but this can be extended to other clusters observed by K2 and, soon, TESS.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-05-24T22:10:26.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "stellar rotation period measurements",
      "k2 m67 study",
      "k2 campaign",
      "mean determining accurate rotation",
      "determining accurate rotation periods"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 55,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}