{
  "id": "1507.06653",
  "version": "v1",
  "published": "2015-07-23T20:00:40.000Z",
  "updated": "2015-07-23T20:00:40.000Z",
  "title": "HST astrometry in the 30 Doradus region: measuring proper motions of individual stars in the Large Magellanic Cloud",
  "authors": [
    "I. Platais",
    "R. P. van der Marel",
    "D. J. Lennon",
    "J. Anderson",
    "A. Bellini",
    "E. Sabbi",
    "H. Sana",
    "L. R. Bedin"
  ],
  "comment": "33 pages, 19 figures (1 in low-res), 3 tables. Accepted for publication in AJ",
  "categories": [
    "astro-ph.SR",
    "astro-ph.GA",
    "astro-ph.IM"
  ],
  "abstract": "We present measurements of positions and relative proper motions in the 30 Doradus region of the Large Magellanic Cloud (LMC). We detail the construction of a single-epoch astrometric reference frame, based on specially-designed observations obtained with the two main imaging instruments ACS/WFC and WFC3/UVIS onboard the Hubble Space Telescope (HST). Internal comparisons indicate a sub milli-arc-second (mas) precision in the positions and the presence of semi-periodic systematics with a mean amplitude of ~0.8 mas. We combined these observations with numerous archival images taken with WFPC2 and spanning 17 years. The precision of the resulting proper motions for well-measured stars around the massive cluster R 136 can be as good as ~20 microarcsec/yr, although the true accuracy of proper motions is generally lower due to the residual systematic errors. The observed proper-motion dispersion for our highest-quality measurements is ~0.1 mas/yr. Our catalog of positions and proper motions contains 86,590 stars down to V~25 and over a total area of ~70 square arcmin. We examined the proper motions of 105 relatively bright stars and identified a total of 6 candidate runaway stars. We are able to tentatively confirm the runaway status of star VFTS 285, consistent with the findings from line-of-sight velocities, and to show that this star has likely been ejected from R 136. This study demonstrates that with HST it is now possible to reliably measure proper motions of individual stars in the nearest dwarf galaxies such as the LMC.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-07-23T20:00:40.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "large magellanic cloud",
      "measuring proper motions",
      "individual stars",
      "doradus region",
      "hst astrometry"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 33,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}