What is the average life span of a supernova?

Answer 1

the nebula stage in a stars life cycle lasts for 25,000 years before turning into a white dwarf and then into a black dwarf.

Answer 2

The average lifespan of a supernova event, from the initial explosion to the fading of the remnant, is typically on the order of a few weeks to a few months.

Answer 3

100,000,000 years

Answer 4

A thousandth of a second.