{
  "id": "1809.08244",
  "version": "v1",
  "published": "2018-09-21T18:00:02.000Z",
  "updated": "2018-09-21T18:00:02.000Z",
  "title": "New ultra-cool and brown dwarf candidates in Gaia DR2",
  "authors": [
    "C. Reylé"
  ],
  "comment": "accepted for publication in A&A, 9 pages",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "Context. The second Gaia data release (Gaia DR2) contains high precision positions, parallaxes and proper motions for 1.3 billion sources. The resulting Hertzsprung-Russel diagram reveals fine structures all over the mass range. Aims. This paper aims to investigate the content of Gaia DR2 at the low-mass end and to characterize ultra-cool and brown dwarfs. Methods. We first retrieve the sample of spectroscopically confirmed ultra-cool and brown dwarfs in Gaia DR2. We use their locus in the precise Hertzsprung-Russel diagram to select new candidates, and to investigate their properties. Results. The number of spectroscopically confirmed objects recovered in Gaia DR2 corresponds to 62 %, and 71 %, of the expected number of objects with and estimated Gaia magnitude Gest $\\leq$ 21.5, and 20.3, respectively, significantly filling the gap with Gaia DR1. Furthermore Gaia DR2 contains ~13 000 $\\geq$M7 and 679 new L candidates. A tentative classification suggests that a few hundreds are young or subdwarf candidates. Their distance distribution shows that the solar neighborhood census is still incomplete. Conclusions. Gaia DR2 offers a great wealth of information on the low-mass objects. It provide a homogeneous and precise catalog of candidates worthwhile to be further characterized with spectroscopic observations.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-09-21T18:00:02.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "brown dwarf candidates",
      "ultra-cool",
      "contains high precision positions",
      "gaia dr2 offers",
      "second gaia data"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 9,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}