{
  "id": "1301.2575",
  "version": "v1",
  "published": "2013-01-11T19:00:29.000Z",
  "updated": "2013-01-11T19:00:29.000Z",
  "title": "Theoretical Modeling of the RR Lyrae Variables in NGC 1851",
  "authors": [
    "Andrea Kunder",
    "Maurizio Salaris",
    "Santi Cassisi",
    "Roberto de Propris",
    "Alistair Walker",
    "Peter B. Stetson",
    "Marcio Catelan",
    "Pia Amigo"
  ],
  "comment": "4 pages, 3 figures. To appear in the proceedings of \"EWASS 2012- Symposium 6: Stellar Populations 55 years after the Vatican conference\", in the Memorie della Societa Astronomica Italiana",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "The RR Lyrae instability strip (IS) in NGC 1851 is investigated, and a model is presented which reproduces the pulsational properties of the RR Lyrae population. In our model, a stellar component within the IS that displays minor helium variations (Y~0.248-0.270) is able to reproduce the observed periods and amplitudes of the RR Lyrae variables, as well as the frequency of fundamental and first-overtone RR Lyrae variables. The RR Lyrae variables therefore may belong to an He-enriched second generation of stars. The RR Lyrae variables with a slightly enhanced helium (Y~0.270-0.280) have longer periods at a given amplitude, as is seen with Oosterhoff II (OoII) RR Lyrae variables, whereas the RR Lyrae variables with Y~0.248-0.270 have shorter periods, exhibiting properties of Oosterhoff I (OoI) variables.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2013-01-11T19:00:29.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "theoretical modeling",
      "rr lyrae instability strip",
      "first-overtone rr lyrae variables",
      "displays minor helium variations",
      "rr lyrae population"
    ],
    "tags": [
      "conference paper"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 4,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1210412
    }
  }
}