Transcript Stars 19.1
Name
the closest star to Earth.
Stars
The Spectrum
Scientists
break down the light from a star
into colors using a spectrum
The spectrum colors from the light show
the star’s temperature and composition.
The pattern of lines also show some of the
elements in the star’s atmosphere.
How do we classify stars?
Temperature:
**Hottest stars
are BLUE or
WHITE
**Coolest stars
are RED or
ORANGE
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
Measuring Distance to Stars
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!
Measured