Eta Carinae: Binarity Confirmed
Abstract
We report the recovery of a spectroscopic event in eta Carinae in 1997/98 after a prediction by Damineli (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 the understanding of the system.
Keywords
Cite
@article{arxiv.astro-ph/9912387,
title = {Eta Carinae: Binarity Confirmed},
author = {Augusto Damineli and Andreas Kaufer and Bernhard Wolf and Otmar Stahl and Dalton F. Lopes and Francisco X. de Araujo},
journal= {arXiv preprint arXiv:astro-ph/9912387},
year = {2009}
}
Comments
13 pages, accepted by ApJ Letters (January 2000)