HR Diagram

Along the top of the diagram you see the different colors of stars. List the colors from left to right.

What variable is found along the x-axis on the HR diagram?

• luminosity (brightness)

• temperature

• life cycle

• popularity

On the Hertzsprung Russell diagram, the x-axis is unusual because it goes in a _______ to ________ direction.

What variable is found along the y-axis on the HR diagram?

• luminosity (brightness)

• temperature

• life cycle

• popularity

Look at the HR diagram and find the group of stars labeled Main Sequence. Which of these is NOT a yellow, main sequence star?

• Procyron

• Sun

• Alpha Centauri A

• Polaris

Look at the HR diagram and find the group of stars labeled Main Sequence. Which of these is a blue, main sequence star?

• Regulus

• Sirius

• Alpha Centauri A

• Rigel

Look at the HR diagram and find the group of stars labeled Main Sequence. Name a red main sequence star.

Now using the HR diagram locate the group of stars labeled Supergiants. The stars in this group are those of at least 100 times the mass of our Sun. Name a white supergiant star.

Now using the HR diagram, locate the group of stars labeled Supergiants. Name the red supergiant stars, choose all that apply.

• Antares

• Betelgeuse

• Bernard's Star

• Polaris

Which star is hotter: Vega or Pollux?

• Vega

• Pollux