In fact, by almost all accounts, it is a red giant.

"So that explains how we got a red giant out of a sun that's only four billion years old."

On the screen was a red giant of a planet.

However, five billion years from now, scientists believe our sun will become a red giant.

"It only means that any evidence of life was destroyed when the sun went red giant."

Some unknown physical process at the surface of the red giant, perhaps?

"At least in that case no life was destroyed when the sun went red giant."

Now, on the other side of the scale were the truly red giants.

This is a red giant with 90 times the Sun's diameter.

A red giant is close to what we call vacuum.