Abstract In low-mass core-collapse supernova (SN) progenitors, nuclear burning beyond oxygen can become explosive under degenerate conditions, triggering eruptive mass loss before the final explosion. We investigate such pre-SN eruptions using SNEC hydrodynamic simulations and realistic stellar models, parameterizing the nuclear energy deposition as a fraction of the binding energy of the combined He layer and H-rich envelope. For the lowest-mass model (9 M ⊙ ), the ejecta mass ( M ej ) scales with the energy gained by the H-rich envelope via a power law (index ∼ 3.5). Across 9–10 M ⊙ , this relation shows limited scatter within a factor of ∼2.6, enabling an estimation of the gained energy from M ej . The shock passage also flattens the bound envelope, which can affect the SN light-curve morphology and provide another diagnostic for the eruption. Then, we compute the associated precursor light curves for the 9 M ⊙ model with the multigroup radiative-transfer code STELLA . These signals are typically faint, with bolometric luminosities of ∼10 39 erg lasting hundreds of days. Their cool blackbody spectra make them brighter in the infrared yet several magnitudes fainter than observed pre-SN precursors at the threshold for full envelope ejection. To aid future studies, we make our posteruption stellar profiles and precursor light curves publicly available.
Zha et al. (Thu,) studied this question.