A search for Type Ia supernova progenitors: the central stars of the planetary nebulae NGC 2392 and NGC 6026

Abstract

We use photoionization modeling to assess the binary nature of the central stars of NGC 2392 and NGC 6026. If they are close binaries, they are potential Type Ia supernova (SN Ia) progenitors if the total mass exceeds the Chandrasekhar limit. We show that the nucleus of NGC 2392 likely has a hot, massive (\simeq 1 Ms) white dwarf companion, and a total mass of ~ 1.6 Ms, making it an especially interesting system. The binary mass in NGC 6026 is less, ~ 1.1 Ms. Even though its orbital period is short, it is not considered to be a SN Ia progenitor.

2 pages, presented at the IAU Symposium 281 "Binary Paths to the Explosions of type Ia Supernovae", Padova, Italy, July 2011