How does a Type Ia supernova originate according to stellar physics?

A white dwarf star accumulates too much mass from a companion star, leading to a runaway thermonuclear explosion.

Type Ia supernovae are defined by a specific mechanism involving binary star systems. In this scenario, a white dwarf star, which is the dense, cooling remnant of a low-to-medium mass star, gravitationally pulls matter, primarily hydrogen and helium, from a nearby companion star. As the white dwarf's mass increases, it eventually surpasses the Chandrasekhar limit. This added mass compresses the core sufficiently to reignite carbon fusion uncontrollably throughout the star, leading to a catastrophic, runaway thermonuclear explosion that completely obliterates the original white dwarf star, leaving nothing behind.