Blackbody Energy

• Open the blackbody simulator BB simulation.

• You should see a curve corresponding to a 6000K blackbody (bb). Move the temperature slider and you will see the curve change shape and the values on the vertical axis

• Click on the box “indicate peak wavelength” and the peak wavelength will appear at the top of the curve.

• Set the temperature to the following temperatures and write down the wavelengths: T=7000K, 3500K, 10500K

• Click on “highlight area under curve”. This area is equivalent to the total amount of light emitted from the star.

• Go down to the bottom right and click on “lock scale”.

• Write down the energy emitted number under Area under Curve for each of the temperatures.
  1. How much more energy does the T=7000 bb output in comparison to the T=3500 bb?

  2. How much more energy does the T=10500K bb output in comparison to the T=3500K bb?

Stars are very similar to blackbodies, they output energy in the same pattern depending on their temperature. Try to answer the following questions to see if you understand the properties of blackbodies

1. How much more energy does a 30,000K star output in comparison to a 6000K star of similar size?

2. Which object appears bluer?

3. Which stars peak emitting wavelength is longer?

4. If a 6000K star has a peak emitting wavelength of approximately 500nm, what is the peak emitting wavelength of the 30,000K star?

5. Which curve has a smaller or more negative B-V index?