{
  "id": "1305.5544",
  "version": "v1",
  "published": "2013-05-23T20:00:16.000Z",
  "updated": "2013-05-23T20:00:16.000Z",
  "title": "Search for Rayleigh scattering in the atmosphere of GJ1214b",
  "authors": [
    "Ernst J. W. de Mooij",
    "Matteo Brogi",
    "Remco J. de Kok",
    "Ignas A. G Snellen",
    "Bryce Croll",
    "Ray Jayawardhana",
    "Henk Hoekstra",
    "Gilles P. P. L. Otten",
    "David H. Bekkers",
    "Sebastiaan Y. Haffert",
    "Josha. J. van Houdt"
  ],
  "comment": "Accepted for publication in ApJ",
  "categories": [
    "astro-ph.EP"
  ],
  "abstract": "We investigate the atmosphere of GJ1214b, a transiting super-Earth planet with a low mean density, by measuring its transit depth as a function of wavelength in the blue optical portion of the spectrum. It is thought that this planet is either a mini-Neptune, consisting of a rocky core with a thick, hydrogen-rich atmosphere, or a planet with a composition dominated by water. Most observations favor a water-dominated atmosphere with a small scale-height, however, some observations indicate that GJ1214b could have an extended atmosphere with a cloud layer muting the molecular features. In an atmosphere with a large scale-height, Rayleigh scattering at blue wavelengths is likely to cause a measurable increase in the apparent size of the planet towards the blue. We observed the transit of GJ1214b in the B-band with the FOcal Reducing Spectrograph (FORS) at the Very Large Telescope (VLT) and in the g-band with both ACAM on the William Hershel Telescope (WHT) and the Wide Field Camera (WFC) at the Isaac Newton Telescope (INT). We find a planet-to-star radius ratio in the B-band of 0.1162+/-0.0017, and in the g-band 0.1180+/-0.0009 and 0.1174+/-0.0017 for the WHT & INT observations respectively. These optical data do not show significant deviations from previous measurements at longer wavelengths. In fact, a flat transmission spectrum across all wavelengths best describes the combined observations. When atmospheric models are considered a small scale-height water-dominated model fits the data best.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2013-05-23T20:00:16.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "atmosphere",
      "rayleigh scattering",
      "wavelength",
      "observations",
      "small scale-height water-dominated model fits"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/0004-637X/771/2/109",
      "journal": "The Astrophysical Journal",
      "year": 2013,
      "month": "Jul",
      "volume": 771,
      "number": 2,
      "pages": 109
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1235373,
      "adsabs": "2013ApJ...771..109D"
    }
  }
}