{
  "id": "0802.3868",
  "version": "v1",
  "published": "2008-02-26T18:44:51.000Z",
  "updated": "2008-02-26T18:44:51.000Z",
  "title": "Early-A stars from IPHAS, and their distribution in and around the Cyg OB2 association",
  "authors": [
    "Janet E. Drew",
    "R. Greimel",
    "M. J. Irwin",
    "S. E. Sale"
  ],
  "comment": "15 pages, 15 figures, accepted for publication in MNRAS",
  "doi": "10.1111/j.1365-2966.2008.13147.x",
  "categories": [
    "astro-ph"
  ],
  "abstract": "Stellar photometry derived from the INT/WFC Photometric H$\\alpha$ Survey of the Northern Galactic Plane (IPHAS) can be used to identify large, reliable samples of A0-A5 dwarfs. For every A star, so identified, it is also possible to derive individual reddening and distance estimates, under the assumption that most selected objects are on or near the main sequence, at a mean absolute r' magnitude of 1.5 -- 1.6. This study presents the method for obtaining such samples and shows that the known reddenings and distances to the open clusters NGC 7510 and NGC 7790 are successfully recovered. A sample of over 1000 A stars is then obtained from IPHAS data in the magnitude range 13.5 < r' < 20 from the region of sky including the massive northern OB association Cyg OB2. Analysis of these data reveals a concentration of ~200 A stars over an area about a degree across, offset mainly to the south of the known 1--3 Myr old OB stars in Cyg OB2: their dereddened r' magnitudes fall in the range 11.8 to 12.5. These are consistent with a ~7 Myr old stellar population at DM = 10.8, or with an age of ~5 Myr at DM = 11.2. The number of A stars found in this clustering alone is consistent with a lower limit to the cluster mass of ~10000 M-sun.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2008-02-26T18:44:51.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "cyg ob2 association",
      "early-a stars",
      "distribution",
      "myr old stellar population",
      "northern ob association cyg ob2"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "Wiley-Blackwell",
      "journal": "Monthly Notices of the Royal Astronomical Society",
      "year": 2008,
      "month": "Jun",
      "volume": 386,
      "number": 4,
      "pages": 1761
    },
    "note": {
      "typesetting": "TeX",
      "pages": 15,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 780068,
      "adsabs": "2008MNRAS.386.1761D"
    }
  }
}