What would happen if the sun went supernova?
When a star goes supernova, a significant amount of its material undergoes fusion is a short period of time. This leads to a massive explosion. Any planets in the vicinity would be exposed to huge temperatures and would be bombarded by huge amounts of radiation and energetic particles.
It is not possible for the Sun to supernova. Even if it was it can only happen at the end of a star's life. The Sun is still main sequence and will be for another 5 billion years.
The only way that a star the size of the Sun could supernova is If it had a younger companion star which was orbiting very close to it.
When the Sun leaves the main sequence it will become a red giant and then collapse into a white dwarf.
When a close companion star becomes a red giant, the white dwarf can accumulate material from the companion. When it has accumulated enough material to be around 1.44 solar masses it will collapse and the temperature and pressure will rise to the point where fusion reactions start which result in a supernova explosion.