Are all stars alike? Discover what makes one star different from another.
Types of Stars
You can see in this picture some of the ways that stars differ from each other.
Stars range in diameter from the smallest neutron stars (20 kilometers) to supergiants with a circumference as big as Jupiter's orbit. Stars fall into the following groups:
- Main Sequence Ninety percent of all stars are main sequence stars. Our sun is a main sequence star.
- Giants and Supergiants After billions of years main sequence stars grow larger and can become giant or supergiant stars.
- White Dwarves These stars are faint. They are formed when a giant star runs out of fuel after millions of years and shrinks.
Classifying the Stars
Three Characteristics of Stars
| Brightness |
Surface Temperature |
Color |
| Stars give off different amounts of light depending on their size and temperature. |
The coolest stars have temperatures of 3,000°C. The hottest stars have temperatures of up to 50,000°C. |
The color of a star is determined by its temperature. Cooler stars are red and the hottest stars are blue. |
Test your knowledge of stars by choosing the correct answer from the pull-down menus in the chart below. Do you need help? Use the Hertzsprung-Russell diagram to find the types, temperatures, and colors of the stars. Click back and forth between the diagram and this page to complete the chart. When you are finished, click SUBMIT. Open the Hertzsprung-Russell Diagram.
