Will the sun ever fail

Answer 1

The Sun is 4.6 billion years old and about halfway through the phase where is shines as it does now due to fusion reactions that convert hydrogen into helium. The Sun will continue this phase, with some variability, until it is about 10 billion years years old.

About 5 billion years from now, the Sun will enter a red giant phase and expand greatly. This lasts for hundreds of millions of years before it blows off its outer layers creating a planetary nebula. In the next several billion years, what is left of the core of the sun will fade to a white dwarf and then continue to cool further forever.

The Sun does not have enough mass to explode as a supernova.