Red Giant Direct

A Red Giant is a star that has depleted its hydrogen fuel in its core and has begun to expand and cool. This occurs when a star like our Sun runs out of hydrogen to fuse into helium in its core. As the hydrogen fuel is used up, the core contracts and heats up, forcing the outer layers of the star to expand. This expansion can be immense, with some Red Giants growing to 100 times their initial size.

Main Sequence: A star like our Sun fuses hydrogen into helium in its core, releasing energy in the form of light and heat. Red Giant

The Red Giant: A Celestial Phenomenon