Question

What are stars made up of and why they shine​

Answer 1

Answer:

Stars shine because they are extremely hot (which is why fire gives off light — because it is hot). The source of their energy is nuclear reactions going on deep inside the stars. In most stars, like our sun, hydrogen is being converted into helium, a process which gives off energy that heats the star.

Answer 2

Stars are huge celestial bodies made mostly of hydrogen and helium that produce light and heat from the churning nuclear forges inside their cores. Stars shine because they have huge fusion reactors in their cores releasing a tremendous amount of energy.