1999/12/17 by Augusto Damineli, A. Damineli, Andreas Kaufer +8 · 1 citation
Physics and Astronomy · #Astro and Planetary Science #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/312441
13 pages, accepted by ApJ Letters (January 2000)
arxiv created 1999/12/17 · openalex publication_date 2000/01/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We report the recovery of a spectroscopic event in eta Carinae in 1997/1998 after a prediction by Damineli in 1996. A true periodicity with P=2020+/-5 days (0.2% uncertainty) is obtained. The line intensities and the radial velocity curve display a phase-locked behavior, implying that the energy and dynamics of the event repeat from cycle to cycle. This rules out S Doradus oscillation or multiple shell ejection by an unstable star as the explanation of the spectroscopic events. A colliding-wind binary scenario is supported by our spectroscopic data and by X-ray observations. Although deviations from a simple case exist around periastron, intensive monitoring during the next event (mid-2003) will be crucial to our understanding of the system.