Star Brightness

Contributor: Rebecca Highland. Lesson ID: 10371

"Star light, star bright . . . "
This child's rhyme brings up a good question: How bright are stars? Learn how and why stars shine!


Space Science and Astronomy

learning style
personality style
Lion, Beaver
Grade Level
Intermediate (3-5)
Lesson Type
Dig Deeper

Lesson Plan - Get It!

Audio: Image - Button Play
Image - Lession Started Image - Button Start
  • Why are some stars in the night sky brighter than others?
  • Have you ever wondered why some stars glow brighter than others?
  • Does a larger star always glow brighter than a smaller one?
  • How do stars even glow in the first place?

Investigate how stars glow, why some stars glow brighter than others, and how stars create energy as you become an astronomer! Study the stars using a fact-filled video, star-studded images, and a fun activity and project.

Let's get started!

As you watch the video below to learn how stars glow and create energy, pause to take notes. Use the questions below as a guide.

  • What is a star?
  • What is nuclear fusion?
  • What happens during nuclear fusion?
  • What gives a star its glow?
  • What is the difference between a star's true and apparent brightness?
  • What is one of the brightest stars in the night sky? What is its size and brightness compared to the sun?

Image - Video

  • Were you able to answer all the questions?

Next, study this diagram of nuclear fusion. Notice how the hydrogen molecules smash or fuse to create helium. The energy then travels toward the star's surface as heat and light, giving the star its glow.

solar fusion diagram

Finally, check out Hubble's Star Clusters: A collection of star clusters images by the Hubble Space Telescope.

  • What do you notice about the different stars?

Keep going in the Got It? section!

Image - Button Next