How do red giants form?

What causes a star to become a red giant?

A star becomes a red giant when it exhausts the hydrogen in its core, leading to fusion of helium and expansion.

Is this process the same for all stars?

Not all stars become red giants; it mainly applies to stars like our Sun, which have sufficient mass to undergo this transformation.

What happens to a red giant after it forms?

After forming, a red giant will eventually shed its outer layers, creating a planetary nebula, and leave behind a white dwarf.

How long does it take for a star to become a red giant?

The process can take millions to billions of years, depending on the star's mass and composition.