How do red giants compare to other stars?

What are red giants and how do they differ from other types of stars?

Red giants are stars that have expanded and cooled after exhausting the hydrogen in their cores. They differ from other stars, like main-sequence stars, in size, temperature, and luminosity.

What causes a star to become a red giant?

A star becomes a red giant when it runs out of hydrogen fuel in its core, leading to fusion of heavier elements and expansion.

How do the sizes of red giants compare to those of main-sequence stars?

Red giants are significantly larger than main-sequence stars. They can be hundreds of times the radius of the Sun!

Are red giants more luminous than other stars?

Yes, red giants are generally more luminous than main-sequence stars due to their larger surface area, despite having lower temperatures.

Can you give examples of famous red giants?

Sure! Some famous red giants include Betelgeuse in Orion and Antares in Scorpius.