Rare events of a peculiar thermonuclear supernova that precedes a core collapse supernova

Ealeal Bear, Noam Soker

Published 2021-03-14Version 1

We study a white dwarf (WD) - neutron star (NS) reverse evolution that might lead to the rare explosion of the WD as a type Ia peculiar supernova (peculiar SN Ia) few months to several years before the core, which is a remnant of a red supergiant (RSG) star, explodes as a core collapse supernova (CCSN). Using the evolutionary code \textsc{mesa-binary} we simulate evolution of binary systems with stars of initial masses of 6-7.5 Mo. The more massive star, the primary, transfers mass to the secondary star and leaves a CO WD remnant of mass ~ 1 Mo. The secondary becomes massive enough to end in a CCSN. As the secondary evolves to the RSG phase it engulfs the WD and the system experience a common envelope evolution that ends with a WD-core binary system at an orbital separation of a_f ~ 1-5 Ro. Our simulations show that the core explodes as a CCSN at t_{CEE-CCSN} ~ 3000 - 10^5 yr after the CEE. The rest of the scenario is speculative. We assume that if the WD accretes helium-rich gas from the core it might explode as a SN Ia in the frame of the double detonation scenario for SNe Ia and peculiar SNe Ia. The peculiar SN Ia explosion might occur at the end of the CEE evolution or just few years before the CCSN. We predict the very rare occurrence of a peculiar SN Ia followed within months to years by a CCSN.