Augusto Damineli, Andreas Kaufer, Bernhard Wolf, Otmar Stahl, Dalton F. Lopes, Francisco X. de Araujo
Published 1999-12-17Version 1
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.
Comments: 13 pages, accepted by ApJ Letters (January 2000)
On the He II Emission In Eta Carinae and the Origin of Its Spectroscopic Events
VLT-UVES observations of the Balmer line variations of eta Carinae during the 2003 spectroscopic event
Accretion by the Secondary in Eta Carinae During the Spectroscopic Event: I. Flow Parameters
