What is required for a white dwarf remnant to cause a Type Ia supernova explosion?

Answer

Accreting mass from a companion star until it approaches the Chandrasekhar limit

A Type Ia supernova occurs when a white dwarf gathers mass from a companion star until it breaches the Chandrasekhar limit, reigniting runaway carbon fusion.

What is required for a white dwarf remnant to cause a Type Ia supernova explosion?
starsupernovaastrophysicsmass