Ignition of carbon burning from nuclear fission in compact stars

TL;DR

This paper explores a novel mechanism for Type-Ia supernovae involving nuclear fission chain reactions in white dwarfs, showing that fission heating at high densities can ignite carbon burning and potentially cause stellar explosions.

Contribution

It introduces a new supernova ignition mechanism based on fission chain reactions in white dwarfs, supported by thermal diffusion simulations.

Findings

Fission heating can ignite carbon burning at densities above 7x10^8 g/cm^3

Fission chain reactions may trigger supernova explosions or transients

Supports a new pathway for Type-Ia supernovae formation

Abstract

Type-Ia supernovae (SN Ia) are powerful stellar explosions that provide important distance indicators in cosmology. Recently, we proposed a new SN Ia mechanism that involves a nuclear fission chain reaction in an isolated white dwarf (WD) [PRL 126, 1311010]. The first solids that form as a WD starts to freeze are actinide rich and potentially support a fission chain reaction. In this letter we explore thermonuclear ignition from fission heating. We perform thermal diffusion simulations and find at high densities, above about 7x10^8 g/cm^3, that the fission heating can ignite carbon burning. This could produce a SN Ia or another kind of astrophysical transient.