Dr. Noam Soker
Technion

University of Florida Astronomy Colloquium - July 28th, 2006

Accretion and Jets in the Eta Carinae Massive Binary System

Eta Carinae is a very massive binary system that underwent a 20 year long eruption about 160 yr ago. This eruption formed a bipolar structure termed the Homunculus. I will argue that the Homunculus was formed during these 20 years as the companion launched two opposite jets by accreting mass from the primary dense stellar wind. This model adds Eta Carinae to a large and diverse group of astrophysical objects where bipolar structures, like a pair of lobes, are formed by jets. Presently the primary stellar wind is not as dense as it was 160 years ago, and accretion does not occur during most of the 5.5 year orbital period. However, for three month near periastron passage the companion's gravity may significantly influence the flow, and the companion might accrete from the primary's wind. Supporting arguments for a short accretion phase, mainly from X-ray observations, will be presented.