Triggering Eruptive Mass Ejection in Luminous Blue Variables

Abstract

We study the runaway mass loss process of major eruptions of luminous blue variables (LBVs) stars, such as the 1837-1856 Great Eruption of Eta Carinae. We follow the evolution of a massive star with a spherical stellar evolution numerical code. After the star exhausted most of the hydrogen in the core and had developed a large envelope, we remove mass at a rate of 1 Mo/year from the outer envelope for 20 years. We find that after removing a small amount of mass at a high rate, the star contracts and releases a huge amount of gravitational energy. We suggest that this energy can sustain the high mass loss rate. The triggering of this runaway mass loss process might be a close stellar companion or internal structural changes. We show that a strong magnetic field region can be built in the radiative zone above the convective core of the evolved massive star. When this magnetic energy is released it might trigger a fast removal of mass, and by that trigger an eruption. Namely, LBV major eruptions might be triggered by magnetic activity cycles. The prediction is that LBV stars that experience major eruptions should be found to have a close companion and/or have signatures of strong magnetic activity during or after the eruption.

Accepted by New Astronomy

References in corpus (12)

• The Structure of the Homunculus: I. Shape and Latitude Dependence from H2 and [Fe II] Velocity Maps of Eta Carinae
• Latitude-dependent effects in the stellar wind of Eta Carinae
• Magnetic Fields in Massive Stars. II. The Buoyant Rise of Magnetic Flux Tubes Through the Radiative Interior
• On the role of the WNH phase in the evolution of very massive stars: Enabling the LBV instability with feedback
• The UV Scattering Halo of the Central Source Associated with Eta Carinae
• Nitrogen and Oxygen Abundance Variations in the Outer Ejecta of Eta Carinae: Evidence for Recent Chemical Enrichment
• The Departure of Eta Carinae from Axisymmetry and the Binary Hypothesis
• Why a Single-Star Model Cannot Explain the Bipolar Nebula of Eta Carinae
• The Structure of the Homunculus. II. Modeling the physical conditions in Eta Car's molecular shell
• On the behaviour of stellar winds that exceed the photon-tiring limit
• Stellar Structure and Mass Loss on the Upper AGB
• Comparing Eta Carinae with the Red Rectangle

Cited by in corpus (15)

• Periastron Passage Triggering of the 19th Century Eruptions of Eta Carinae
• 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
• Was the nineteenth century giant eruption of Eta Carinae a merger event in a triple system?
• Wave-driven stellar expansion and binary interaction in pre-supernova outbursts
• NGC 300 OT2008-1 As a Scaled-Down Version of the Eta Carinae Great Eruption
• Simulating the formation of $\eta$ Carinae's surrounding nebula through unstable triple evolution and stellar merger-induced eruption
• Powering the Second 2012 Outburst of SN 2009ip by Repeating Binary Interaction
• Recurring X-ray Outbursts in the Supernova Impostor SN~2010da in NGC~300
• Exceptionally fast ejecta seen in light echoes of Eta Carinae's Great Eruption
• Recovery from Giant Eruptions in Very Massive Stars
• Pre-explosion dynamo in the cores of massive stars
• Luminous Blue Variables
• Storing magnetic fields in pre-collapse cores of massive stars
• Giant outbursts of clumpy material preceding Type II supernova 2024qiw