Detection of a Hot Binary Companion of η Carinae
Abstract
We report the detection of a hot companion of η Carinae using high resolution spectra (905 - 1180 ) obtained with the Far Ultraviolet Spectroscopic Explorer () 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 ηcar shortward of disappeared at least two days before the start of the X-ray eclipse (2003 June 29), implying that the hot companion, ηB, was also eclipsed by the dense wind or extended atmosphere of ηA. Analysis of the far-UV spectrum shows that ηB is a luminous hot star. The 1084-1086 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 ηcar\ being a massive binary system.
Turn this paper into a full lesson
ArcXiv compiles a staged curriculum from this paper: 8-12 lessons across beginner → advanced, synthesised section guides, visuals, flashcards, a quiz, exercises, and on-demand deep dives per section. Grounded in the abstract, never invented.