{
  "id": "1406.7066",
  "version": "v1",
  "published": "2014-06-27T05:23:45.000Z",
  "updated": "2014-06-27T05:23:45.000Z",
  "title": "Spectroscopic Study on the Beryllium Abundances of Red Giant Stars",
  "authors": [
    "Yoichi Takeda",
    "Akito Tajitsu"
  ],
  "comment": "29 pages, 10 figures, 3 tables, accepted for publication in Publ. Astron. Soc. Japan",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "An extensive spectroscopic study was carried out for the beryllium abundances of 200 red giants (mostly of late G and early K type), which were determined from the near-UV Be II 3131.066 line based on high-dispersion spectra obtained by Subaru/HDS, with an aim of investigating the nature of surface Be contents in these evolved giants; e.g., dependence upon stellar parameters, degree of peculiarity along with its origin and build-up timing. We found that Be is considerably deficient (to widely different degree from star to star) in the photosphere of these evolved giants by ~1-3 dex (or more) compared to the initial abundance. While the resulting Be abundances (A(Be)) appear to weakly depend upon T_eff, log g, [Fe/H], M, age, and v_sin i, this may be attributed to the metallicity dependence of A(Be) coupled with the mutual correlation between these stellar parameters, since such tendencies almost disappear in the metallicity-scaled Be abundance ([Be/Fe]). By comparing the Be abundances (as well as their correlations with Li and C) to the recent theoretical predictions based on sophisticated stellar evolution calculations, we concluded that such a considerable extent/diversity of Be deficit is difficult to explain only by the standard theory of first dredge-up in the envelope of red giants, and that some extra mixing process (such as rotational or thermohaline mixing) must be responsible, which presumably starts to operate already in the main-sequence phase. This view is supported by the fact that appreciable Be depletion is seen in less evolved intermediate-mass B-A type stars near to the main sequence.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2014-06-27T05:23:45.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "red giant stars",
      "beryllium abundances",
      "spectroscopic study",
      "stellar parameters",
      "evolved intermediate-mass b-a type stars"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1093/pasj/psu066",
      "journal": "Publications of the Astronomical Society of Japan",
      "year": 2014,
      "month": "Oct",
      "volume": 66,
      "number": 5,
      "pages": 91
    },
    "note": {
      "typesetting": "TeX",
      "pages": 29,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2014PASJ...66...91T"
    }
  }
}