Abstract

The nature of the periodic events in eta Carinae: collapse of the wind-wind collision.

Augusto Damineli (IAGUSP)

Mairan Teodoro - IAGUSP

The 5.5-yr low excitation events in eta Carinae are interpreted as due to the periastron passages of the companion stars in a very eccentric orbit. Although this is a consensus between the many authors, there is no consensus about the mechanism of the events. We show that they are not due to eclipses or any mechanism that works only close to periastron, like shell ejection. Our interpretation is that the wind-wind collision zone collapses onto the surface of the secondary star. The recovery from the minimum is governed by physical conditions at very small scales, leading to variability from cycle to cycle.