Depending on where fusion restarts inside the white dwarf and the amount the white dwarfs receives mass too quickly from a companion star, it can become a Type 1A Supernova, which is the 1.4M? times the gravity stronger than the electron degeneracy pressure. the Chandrasekhar limit allows astronomers to estimate distances and this is how we understand the difference between when a white dwarf remains a gentle nova or else become Type 1A Supernova.