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Abstract Eruptive mass loss in massive stars is known to occur, but the mechanism(s) are not yet well understood. One proposed physical explanation appeals to opacity-driven super-Eddington luminosities in stellar envelopes. Here, we present a 1D model for eruptive mass loss and implement this model in theMESAstellar evolution code. The model identifies regions in the star where the energy associated with a local super-Eddington luminosity exceeds the binding energy of the overlaying envelope. The material above such regions is ejected from the star. Stars with initial masses of 10−100M_⊙at solar and SMC metallicities are evolved through core helium burning, with and without this new eruptive mass-loss scheme. We find that eruptive mass loss of up to ∼10⁻²M_⊙yr⁻¹can be driven by this mechanism, and occurs in a vertical band on the H-R diagram between $3.5\lesssim \log \left(T_{\mathrm{eff}}/\mathrm{K}\right)\lesssim 4.0$. This predicted eruptive mass loss prevents stars of initial masses ≳20M_⊙from evolving to become red supergiants (RSGs), with the stars instead ending their lives as blue supergiants, and offers a possible explanation for the observed lack of RSGs in that mass regime. 

Abstract Core-collapse supernovae (SNe) are candidate sites for rapid neutron capture process (r-process) nucleosynthesis. We explore the effects of enrichment fromr-process nuclei on the light curves of hydrogen-rich SNe and assess the detectability of these signatures. We modify the radiation hydrodynamics code, SuperNova Explosion Code, to include the approximate effects of opacity and radioactive heating fromr-process elements in the supernova (SN) ejecta. We present models spanning a range of totalr-process massesM_rand their assumed radial distribution within the ejecta, finding thatM_r≳ 10⁻²M_⊙is sufficient to induce appreciable differences in their light curves as compared to ordinary hydrogen-rich SNe (without anyr-process elements). The primary photometric signatures ofr-process enrichment include a shortening of the plateau phase, coinciding with the hydrogen-recombination photosphere retreating to ther-process-enriched layers, and a steeper post-plateau decline associated with a reddening of the SN colors. We compare ourr-process-enriched models to ordinary SNe models and observational data, showing that yields ofM_r≳ 10⁻²M_⊙are potentially detectable across several of the metrics used by transient observers, provided thatr-process-rich layers are mixed at least halfway to the ejecta surface. This detectability threshold can roughly be reproduced analytically using a two-zone (kilonova-within-an-SN) picture. Assuming that a small fraction of SNe produce a detectabler-process yield ofM_r≳ 10⁻²M_⊙, and respecting constraints on the total Galactic production rate, we estimate that ≳10³–10⁴SNe need be observed to find oner-enriched event, a feat that may become possible with the Vera Rubin Observatory.