Comparing Eta Carinae with the Red Rectangle

Abstract

I compare the structures of the bipolar nebulae around the massive binary system Eta Carinae and around the low mass binary system HD 44179. While Eta Carinae is on its way to become a supernova, the Red Rectangle is on its way to form a planetary nebula. Despite the two orders of magnitude difference in mass, these two systems show several similarities, both in the properties of the stellar binary systems and the nebulae. From this comparison and further analysis of the accretion process during the 20 years Great Eruption of Eta Carinae, I strengthen the binary model for the formation of its bipolar nebula--the Homunculus. In the binary model a large fraction of the mass lost by the primary star during the Great Eruption was transferred to the secondary star (the companion); An accretion disk was formed around the companion, and the companion launched two opposite jets. I show that the gravitational energy of the mass accreted onto the secondary star during the Great Eruption can account for the extra energy of the Great Eruption, both the radiated energy and the kinetic energy in the Homunculus. I also conclude that neither the proximity of the primary star in Eta Car to the Eddington luminosity, nor the rotation of the primary star are related directly to the shaping of the Homunculus. I speculate that the Great Eruption of Eta Carinae was triggered by disturbance in the outer boundary of the convective region, most likely by magnetic activity, that expelled the outer radiative zone.

ApJ, in press (small changes from original version)

References in corpus (5)

• On the role of continuum-driven eruptions in the evolution of very massive stars and Population III stars
• The Structure of the Homunculus: I. Shape and Latitude Dependence from H2 and [Fe II] Velocity Maps of Eta Carinae
• AG Carinae: a Luminous Blue Variable with a high rotational velocity
• The Structure of the Homunculus. II. Modeling the physical conditions in Eta Car's molecular shell
• Bubbles in Planetary Nebulae and Clusters of Galaxies: Jet Bending

Cited by in corpus (24)

• High-excitation emission lines near eta Carinae, and its likely companion star
• Periastron Passage Triggering of the 19th Century Eruptions of Eta Carinae
• Constraining the Absolute Orientation of Eta Carinae's Binary Orbit: A 3-D Dynamical Model for the Broad [Fe III] Emission
• Formation of Bipolar Planetary Nebulae by Intermediate-Luminosity Optical Transients
• Explosions Triggered by Violent Binary-Star Collisions: Application to Eta Carinae and other Eruptive Transients
• A Model for the 19th Century Eruption of Eta Carinae: CSM Interaction Like a Scaled-Down Type IIn Supernova
• Possible Implications of Mass Accretion in Eta Carinae
• Simulating the formation of $\eta$ Carinae's surrounding nebula through unstable triple evolution and stellar merger-induced eruption
• Ancient eruptions of Eta Carinae: A tale written in proper motions
• The three-dimensional structure of the Eta Carinae Homunculus
• Efficiently jet-powered radiation in intermediate-luminosity optical transients (ILOTS)
• Light Echoes from Eta Carinae's Great Eruption: Spectrophotometric Evolution and the Rapid Formation of Nitrogen-rich Molecules
• Forming equatorial rings around dying stars
• Using X-Ray Observations to Explore the Binary Interaction in Eta Carinae
• Modelling the Radio Light Curve of Eta Carinae
• Triggering Eruptive Mass Ejection in Luminous Blue Variables
• Accretion onto the Companion of Eta Carinae During the Spectroscopic Event. IV. the Disappearance of Highly Ionized Lines
• Explaining recently studied intermediate luminosity optical transients (ILOTs) with jet powering
• Mid-Cycle Changes in Eta Carinae
• Bipolar rings from jet-inflated bubbles around evolved binary stars
• The Formation of Slow-Massive-Wide Jets
• Luminous Blue Variables
• Explaining the transient fast blue absorption lines in the massive binary system Eta Carinae
• On the 3D structure of the nebula around η-Carinae