• An important physical characteristic of stars is brightness.
• All stars except the sun are so far away from Earth that many seem equally as bright in the night sky.
  • Astronomers call this measure of brightness apparent magnitude.
• It is independent of the star's distance or characteristics. Even a dim star can appear brighter compared to a much brighter star, if the brighter star is much further away.

Review

• Q: What is the definition of apparent magnitude?
• A: How bright a star appears from Earth