{
  "id": "1310.7591",
  "version": "v1",
  "published": "2013-10-28T20:00:12.000Z",
  "updated": "2013-10-28T20:00:12.000Z",
  "title": "The Mass-Radius Relationship for Very Low Mass Stars: Four New Discoveries from the HATSouth Survey",
  "authors": [
    "G. Zhou",
    "D. Bayliss",
    "J. D. Hartman",
    "G. Á. Bakos",
    "K. Penev",
    "Z. Csubry",
    "T. G. Tan",
    "A. Jordán",
    "L. Mancini",
    "M. Rabus",
    "R. Brahm",
    "N. Espinoza",
    "M. Mohler-Fischer",
    "S. Ciceri",
    "V. Suc",
    "B. Csák",
    "T. Henning",
    "B. Schmidt"
  ],
  "comment": "17 pages, 8 figures, accepted for publication in MNRAS",
  "categories": [
    "astro-ph.SR",
    "astro-ph.EP"
  ],
  "abstract": "We report the discovery of four transiting F-M binary systems with companions between 0.1-0.2 Msun in mass by the HATSouth survey. These systems have been characterised via a global analysis of the HATSouth discovery data, combined with high-resolution radial velocities and accurate transit photometry observations. We determined the masses and radii of the component stars using a combination of two methods: isochrone fitting of spectroscopic primary star parameters, and equating spectroscopic primary star rotation velocity with spin-orbit synchronisation. These new very low mass companions are HATS550-016B (0.110 -0.006/+0.005 Msun, 0.147 -0.004/+0.003 Rsun), HATS551-019B (0.17 -0.01/+0.01 Msun, 0.18 -0.01/+0.01 Rsun), HATS551-021B (0.132 -0.005/+0.014 Msun, 0.154 -0.008/+0.006 Rsun), HATS553-001B (0.20 -0.02/+0.01 Msun, 0.22 -0.01/+0.01 Rsun). We examine our sample in the context of the radius anomaly for fully-convective low mass stars. Combining our sample with the 13 other well-studied very low mass stars, we find a tentative 5% systematic deviation between the measured radii and theoretical isochrone models.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2013-10-28T20:00:12.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "low mass stars",
      "hatsouth survey",
      "mass-radius relationship",
      "spectroscopic primary star rotation velocity",
      "spectroscopic primary star parameters"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1093/mnras/stt2100",
      "journal": "Monthly Notices of the Royal Astronomical Society",
      "year": 2014,
      "month": "Jan",
      "volume": 437,
      "number": 3,
      "pages": 2831
    },
    "note": {
      "typesetting": "TeX",
      "pages": 17,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2014MNRAS.437.2831Z"
    }
  }
}