Pre-Supernova Multiple Giant Eruptions in Massive Stars

TL;DR

This study models multiple giant eruptions in massive stars before supernovae, revealing how these eruptions affect stellar recovery, luminosity, and potential for subsequent eruptions, with implications for understanding pre-supernova stellar behavior.

Contribution

It introduces a detailed simulation of multiple giant eruptions in a 100 solar mass star, analyzing their effects on stellar recovery and conditions for future eruptions, considering different mass loss rates and metallicities.

Findings

Eruptions decrease luminosity and slightly increase temperature.

Recovery times vary with mass loss rate and metallicity.

High mass-loss rates induce outer layer oscillations and compression.

Abstract

Massive stars can exhibit giant eruptions with high mass loss shortly before their explosion as a core-collapse Supernova. These multiple giant eruptions (MGEs) may have a commutative effect that brings the star to a different state, possible one that favors the explosion. To address this problem, we evolve a 100 solar mass star and initiate a series of three giant eruptions lasting one year each, testing different mass loss rates and different metallicities. Following each eruption, we track the recovery phase to examine the post-eruption behavior of the star and its recovery timescale. The MGEs lead to a decrease in luminosity, accompanied by a slight increase in temperature. Later, during the recovery phases as the star starts to retain its equilibrium state, its luminosity increases. The recovery time-scale varies significantly after each eruption for independent on the mass loss rate, but it is shorter for lower metallicities. For the higher mass-loss rates during the recovery phase, the outer layers of the star exhibit oscillations and undergo compression at higher metallicity. These oscillations are most likely a consequence of thermal imbalance in the outer envelope. This behavior at higher mass-loss rates also suggests that the thermal readjustments during recovery may create favorable conditions for a subsequent eruption of the star.