At the end of the stars phase for our sun, it will not become a supernova which is when a star gets a lot brighter because of an explosions that ejects pretty much most of it’s mass. I think that would be pretty cool if that was the fate of our sun. Apparently, our sun isn’t big enough for that. ?? Our sun is HUGE! Yes, it is huge compared to us, but not to lots of other high mass stars in the universe. In about 5 billion years it will enter a red giant phase and then it will steadily expand. Earth wont have to worry about the expansion of the Sun in the Red Giant Phase because earth will be gone in 1 billion years because the sun gets brighter by 10% ever billion years. In 1 billion years, the Earths surface temperature will with so hot that water wont be able to exist. So, yeah the fate of the Earth is pretty dark. So have no fear that the sun will explode into a supernova, it will go straight to the red giant phase before coming a planetary nebula and the Sun will expand so far that it will exceed Earth’s path but don’t worry because earth will be dried up and no trace of human existence will ever be seen to exist. It is pretty cool the see the Suns fate, but, not the Earths!