1. Star Classification Activity

2. A star is an enormous, hot ball of gas held together by gravity.
The gravity is so strong that it causes nuclear fusion.
Stars are the only objects that heat and light the planets in a system.
A star is a huge ball of gas, usually made of Hydrogen (H) and Helium (He).

3. The ball of fire also gives off all kinds of light
The ball of fire also gives off all kinds of light. There are visible rays, UV rays, infrared rays, radio waves and x-rays constantly emitted into space.
Astronomers look at three main characteristics of stars. They study luminosity, temperature, and mass (size).

4. Analysis and Conclusion
Luminosity – the amount of light emitted from the star’s surface. 5. What is the difference between luminosity and the apparent brightness of a star?