Eta car: The good, the bad and the ugly of nebular and stellar confusion

K. E. Nielsen, G. Vieira Kober, T. R. Gull, R. Iping, D. J. Hillier, G. Sonneborn, A. G. Jensen

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Observations in the far-UV provide a unique opportunity to investigate the very massive star 7] Car and its hot binary companion, 7] Car B. 7] Car was observed with FUSE over a large portion of the 5.54 year spectroscopic period before and after the 2003.5 minimum. The observed spectrum is defined by strong stellar wind signatures, primarily from 7] Car A, complicated by the strong absorptions of the ejecta surrounding 7] Car plus interstellar absorption. The Homunculus and Little Homunculus are massive bipolar ejecta historically associable with LBV outbursts in the 1840s and the 1890s and are linked to absorptions at -513 and -146 km s- 1, respectively. The FUSE spectra are confused by the extended nebulosity and thermal drifting of the FUSE co-pointed instruments. Interpretation is further complicated by two B-stars sufficiently close to 7] Car to be included most of the time in the large FUSE aperture. Followup observations partially succeeded in obtaining spectra of at least one of these B-stars through the smaller apertures, allowing potential separation of the B-star contributions and 7] Car. A complete analysis of all available spectra is currently underway. Our ultimate goals are to directly detect the hot secondary star i f possible with FUSE and to identify the absorption contributions to the overall spectrum especially of the stellar members and the massive ejecta.

Original languageEnglish (US)
Title of host publicationFuture Directions in Ultraviolet Spectroscopy - A Conference Inspired by the Accomplishments of the Far Ultraviolet Spectroscopic Explorer Mission
Number of pages3
StatePublished - 2009
Externally publishedYes
EventFuture Directions in Ultraviolet Spectroscopy Conference - Annapolis, MD, United States
Duration: Oct 20 2008Oct 22 2008

Publication series

NameAIP Conference Proceedings
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616


OtherFuture Directions in Ultraviolet Spectroscopy Conference
CountryUnited States
CityAnnapolis, MD


  • Individual stars: eta carinae
  • Spectroscopy

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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