Answer :
After the Sun exhausts the hydrogen fuel in its core and transitions from its main sequence phase, several key changes will occur in its evolution:
Red Giant Phase: The core of the Sun will contract and heat up while the outer layers will expand, causing the Sun to become a red giant. During this phase, the outer layers of the Sun will engulf Mercury and Venus, and possibly Earth as well, though opinions differ on this.
Helium Burning: In the core of the red giant, helium fusion will begin as the temperature and pressure increase enough to fuse helium into carbon through the triple-alpha process. This process will cause the Sun to swell to several hundred times its current size.
The sun will end its life as a white dwarf. As a white dwarf, it is essentially a dead star that has exhausted all of the nuclear fuel that it is capable of burning. As a white dwarf, it will slowly cool and fade away to lower and lower temperatures. This is the final state of low-mass stars, including the sun.Mar 6, 2024
