Classifying Stars Stars are classified by 3 Main Characteristics: 1. Size 2. Temperature 3. Brightness

Hottest (20,000-50,000*C) : (10,000*C) (6,000*C) (4,000-5,000*C) Color reveals the temperature of a star. Hottest (20,000-50,000*C) : (10,000*C) (6,000*C) (4,000-5,000*C) (3000*C) Blue White Yellow Red-Orange Red

Brightness of Stars Apparent Magnitude: Brightness as seen from earth Absolute Magnitude: Brightness of a star from a standard distance

Hertzsprung-Russell Diagram A graph plotting brightness and temperature. 90% of stars are Main Sequence