Read this main idea: Scientists use special tools to study stars. Choose three details that go with the main idea.

Astronomers long ago and today use star charts to map star locations.
The largest stars, called supergiants, are 1,500 times bigger than our sun.
Stars can be blue, white, yellow, or red. Blue stars are the hottest.
The sun's gravity holds the planets in place. It provides them with heat and light.
Our sun is not the largest or hottest star. It is a medium sized yellow star.
All of the planets in our solar system revolve around one star-our sun.
Radio telescopes use radio waves to show stars in great detail.
A reflector telescope bounces star light through mirrors.
It takes Earth 365 days to orbit the sun. Jupiter takes 12 years!