1. Add to table of contents:
Color the Spectra Pg. 8
Electromagnetic spectrum Pg. 9

2. Herztsprung-Russell Diagram
Attach to the top of page 9.

4. Herztsprung-Russell Diagram
Use the H-R diagram to answer the following questions:
What is meant by the word “magnitude”?
What color are cooler stars?
What color are hot stars?
What are main sequence stars?
What category of star is our sun?
Using the diagram, how would you describe our sun?

5. Luminosity = Magnitude = brightness

6. Electromagnetic spectrum
Stars emit all forms of electromagnetic energy.
We can only see a very small part of it = visible light = colors.

7. Draw on page 9
Short wavelength
Long wavelength

8. Visible light questions:
What colors are on the visible light spectrum?
What units are the wavelengths of light measured in? µm = micrometers or nm=nanometers
What is the range of wavelengths of visible light?
Which color has the longest wavelength?
Which color has the shortest wavelength?
What color would you expect to see at a wavelength of 0.45 micrometers?
What color would you expect to see at 0.7 micrometers?

9. Every element, when illuminated, gives off an unique set of spectral lines called a “spectral fingerprint”.

10. A spectral fingerprint tells us:
what gases(elements) are in a star
how hot it is
If it is moving towards us or away (blue shift/red shift)

11. Assignment:Color spectral fingerprints
Color each line indicated on the spectral fingerprint worksheet.

12. 1. Hydrogen

13. 2. Helium

14. 3. Carbon

15. 4. Oxygen 410,413,423,440, , 478,480 –blues red-640,650,668,672
Green-520, 533, yellow-593,599, orange-610,618,630

16. Combine H and He for #5
Copy lines from #1 H and # 2 He onto the line for #5. This is what happens when we are seeing more than 1 element’s light at the same time.