• DOI:10.1086/498268
• Corpus ID: 16147994

Detection of a hot binary companion of η carinae

@article{Iping2005DetectionOA,
  title={Detection of a hot binary companion of $\eta$ carinae},
  author={Rosina C. Iping and George Sonneborn and Theodore R. Gull and Derck Massa and D. John Hillier},
  journal={The Astrophysical Journal},
  year={2005},
  volume={633}
}

• R. Iping, G. Sonneborn, +2 authors D. Hillier
• Published 17 October 2005
• Physics
• The Astrophysical Journal

We report the detection of a hot companion of η Carinae using high-resolution spectra (905-1180 A) obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. Observations were obtained at two epochs of the 2024 day orbit: 2003 June, during ingress to the 2003.5 X-ray eclipse, and 2004 April, several months after egress. These data show that essentially all the far-UV flux from η Car shortward of Lyα disappeared at least 2 days before the start of the X-ray eclipse (2003 June 29), implying that the hot companion, η Car B, was also eclipsed by the dense wind or extended atmosphere of η Car A. Analysis of the far-UV spectrum shows that η Car B is a luminous, hot star. The N II λλ1084-1086 emission feature suggests that it may be nitrogen-rich. The observed far-UV flux levels and spectral features, combined with the timing of their disappearance, is consistent with η Car being a massive binary system.