Title: Type Iax Supernovae: Extreme Thermonuclear Explosions

Abstract: Thermonuclear supernovae signal the explosive ends of white dwarfs in binary systems. The most commonly observed thermonuclear supernovae, type Ia, are of particular importance given their role as cosmological distance indicators. In spite of this however, the nature of the explosion and progenitor system in type Ia supernovae remains a mystery. By studying variations of thermonuclear supernovae, we can begin to solve the puzzle of why some white dwarfs explode in one way and the observational signatures that should be expected. In this talk, I will present an overview of perhaps the most numerous class of peculiar type Ia supernovae: type Iax. I will cover the main observational properties of the class and discuss how these provide constraints on the likely explosion mechanism(s) and progenitor system(s). I will demonstrate that the theoretical understanding of type Iax supernovae is on much firmer ground than for classical thermonuclear supernovae, despite their more recent discovery and being less well-observed.