Presupernova Multiple Giant Eruptions in Massive Stars

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, possibly one that favors the explosion. To address this problem, we evolve a 100 M ⊙ star and initiate a series of three giant eruptions lasting 1 year each, testing different mass-loss rates and different metallicities. Following each eruption, we track the recovery phase to examine the posteruption 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 timescale varies significantly after each eruption, independent of the mass-loss rate, but it is shorter for lower metallicities. For 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 thermal readjustments during recovery may create favorable conditions for a subsequent eruption of the star.