Come on, it's realy criticall issue! Sun doesn't explode at high age, it should become red giant. Very criticall error, and confusing people.
The sun is to small of a star to go supernova.
When it dies, the sun will swell up into a red giant star and possibly take the first three inner planets when this happens. After that phase, it will expel its out layers into space and slowly become a white dwarf.
And the nebulae left behind will be a planetary nebulae.
If you would like to know what a planetary nebulae looks like, just search for the cat eye nebulae.
Its also a planetary nebulae.