Hertzsprung- Russell Diagram
Hertzsprung-Russell Diagram
H-R Diagram
• Compares the temperature, color and luminosity (brightness) of stars on a graph.
• The temperature is the surface temperature of the star
• The brightness of the star is its absolute magnitude
APPARENT MAGNITUDE VS.
ABSOLUTE MAGNITUDE
Apparent magnitude
Absolute magnitude
Measure of the amount of a star’s light received on Earth
Measure of the amount of lighta star actually gives off
STAR PROPERTIES
Color indicates temperature
Hot stars are
Cool stars are
YellowMedium temperature stars are
Blue
Red
White dwarfs
small, hot stars
leftover centers of old stars
Red-Giants
When star runs out of energy, the center shrinks and the outer part expands outward. It will grow very large and cool.
Supergiants
Very massive cool giant star
Main Sequence
Stretches diagonal from the top left to the right bottom
Our sun is an average main sequence star
Blue Supergiants
Very massive blue stars
Quickly use up energy and turn into Giants or Supergiants
Red Dwarfs
Low-mass stars
Oldest stars in galaxy
Putting it all together
http://www.eram.k12.ny.us/education/sctemp/77f43cfb9ae82b830c63fb080599aa31/hr.swf
H-R Diagram AND Life Cycle