Interacting Binary Stars as Progenitors for Interacting Supernovae

TL;DR

This study demonstrates that late-stage Case C mass transfer in binary stars naturally creates dense circumstellar media, explaining the environments of interacting supernovae without invoking rare or ad hoc mechanisms.

Contribution

It shows that Case C mass transfer in binary evolution can account for the dense CSM observed in many interacting supernovae, a previously underappreciated channel.

Findings

Case C mass transfer ejects 0.01-0.2 solar masses of material.

The resulting CSM extends to 10^16-10^18 cm.

Approximately 13% of CCSN progenitors may undergo this process.

Abstract

Dense, compact circumstellar media (CSM) are required to power strongly interacting supernovae, yet their physical origin remains uncertain. We present a systematic study of binary stellar evolution models computed with MESA, demonstrating that Case C mass transfer, initiated after core helium ignition, can naturally produces the dense, nearby CSM inferred in interacting events. Across a grid of binary models, we find that donors of 10--20 solar masses in binaries with separations of approximately 1000--2700 solar radius undergo late-stage Roche-lobe overflow within ~10^3 yr prior to core collapse, ejecting ~0.01--0.2 solar masses and forming CSM extending to ~10^16--10^18 cm. Our results suggest that the Case C mass transfer may account for ~13% of all core-collapse supernova (CCSN) progenitors, rather than representing a rare channel. A subset of these Case C binaries produces CSM properties that are quantitatively in agreement with those inferred for interacting supernovae such as SN 2014C. In contrast to earlier binary interactions or single-star mass loss, Case C transfer operates at the right time and scale to shape the immediate pre-supernova environment without requiring ad hoc eruptive mechanisms. Our results identify late-stage binary interaction as a robust and physically motivated channel for producing the dense CSM that powers interacting supernovae.