🔍 Key Concepts

• Magnitude in astronomy refers to how bright a star appears, not its size or position • Declination and SHA (Sidereal Hour Angle) describe a star’s position on the celestial sphere, similar to latitude and longitude on Earth • A variable star is classified based on what aspect of the star is changing over time

💭 Think About

• Ask yourself: when astronomers call a star "variable," what specific property are they usually measuring again and again? • Which of the choices are about position in the sky, and which are about how the star appears to an observer? • Does the term "red giant" describe a type of star, or what is changing about the star?

✅ Before You Answer

• Identify which options describe position (declination or SHA) rather than a changing property • Recall that astronomical magnitude is a measure of brightness, not physical size • Separate star type (like red giant) from what makes a star a variable star