How does sun form?what happen when sun dead?
From other stars, astronomers found that the sun most likely started out as a large collapsing cloud of gas inside some interstellar clout.
The cloud collapsed for millions of years, until it formed a rotating disk with a large central bulge.
And inside the rotating disk, bits of matter will eventually collide and begin to form our planets. And one of those planets will be Earth!
The central bulge repeatedly collapsing under its own gravity until the temperatures in the core got so high that deuterium atoms (an isotope of hydrogen) began to fuse and give off thermonuclear energy. This caused the continuous collapse to slow down and eventually led the sun to its second stage; where Hydrogen nuclei begin to fuse into Helium. This is what started the sun’s current evolutionary phase.
When sun dies:
Stars are born, they live, and they die. The sun is no different, and when it goes, the Earth goes with it. But our planet won't go quietly into the night.Rather, when the sun expands into a red giant during the throes of death, it will vaporize the Earth.