Name the closest star to Earth.

1
Warm Up

• Name the closest star to Earth.

2
Stars
3
The Spectrum

• Scientists break down the light from a star into
  colors using a spectrum
• The spectrum colors from the light show the
  stars temperature and composition.
• The pattern of lines also show some of the
  elements in the stars atmosphere.

4
How do we classify stars?

• Temperature
• Hottest stars are BLUE or WHITE
• Coolest stars are RED or ORANGE

5
How do we classify stars?

• Brightness
• The amount of light the star gives off
• Depends on size and temperature
• Large cooler ? bright
• Small hot ? bright
• Apparent Magnitude How bright the star appears
  from Earth closer brighter
• Absolute Magnitude How bright the star is
  actually shining hard to determine

6
Measuring Distance to Stars

• Measured in light years LY
• LY the distance light travels in 1 yr. It is a
  measurement of distance not time.
• 300,000 km per second!
• Closest star is Proxima Centauri at 4.2 LY away.
  Traveling 300,000 km per second it would take 4.2
  Earth years to get there!