{
  "id": "astro-ph/0412453",
  "version": "v1",
  "published": "2004-12-17T09:58:33.000Z",
  "updated": "2004-12-17T09:58:33.000Z",
  "title": "VLT-UVES observations of the Balmer line variations of eta Carinae during the 2003 spectroscopic event",
  "authors": [
    "Kerstin Weis",
    "Otmar Stahl",
    "Dominik J. Bomans",
    "Kris Davidson",
    "Theodore R. Gull",
    "Roberta M. Humphreys"
  ],
  "comment": "11 pages, 8 figures, to appear in AJ March issue, paper with images in full resolution at http://www.astro.rub.de/kweis/publications.html",
  "doi": "10.1086/428005",
  "categories": [
    "astro-ph"
  ],
  "abstract": "We present high spectral resolution echelle observations of the Balmer line variations during the 2003.5 ``spectroscopic event'' of eta Carinae. Spectra have been recorded of both eta Carinae and the Homunculus at the FOS4 position in its SE lobe. This spot shows a reflected stellar spectrum which is less contaminated by nebular emission lines than ground-based observations of the central object itself. Our observations show that the spectroscopic event is much less pronounced at this position than when seen directly on eta Car using HST/STIS. Assuming that the reflected spectrum is indeed latitude dependent this indicates that the spectral changes during the event seen pole-on (FOS4) are different from those closer to the equator (directly on the star). In contrast to the spectrum of the star, the scattered spectrum of FOS4 always shows pronounced P Cygni absorption with little variation across the ``spectroscopic event''. After that event an additional high-velocity absorption component appears. The emission profile is more peaked at FOS4 and consists of at least 3 distinct components, of which the reddest one shows the strongest changes through the event. The data seem to be compatible with changes in latitudinal wind structure of a single star, with or without the help of a secondary star, or the onset of a shell ejection during the spectroscopic event.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2004-12-17T09:58:33.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "spectroscopic event",
      "balmer line variations",
      "eta carinae",
      "vlt-uves observations",
      "additional high-velocity absorption component appears"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 11,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 667337
    }
  }
}