1. Astronomy: A Self-Teaching Guide
Ch. 03: The Stars
1. The method of __________ is used in measuring the distances to nearby stars.
2. 1 parsec = ____________________ light years
3. How is the parsec related to the parallax method?
4. List the three types of spectra.
5. Compare emission and absorption lines to the placement of electrons around the nucleus of an
atom.
6. Describe how a star can emit both continuous and absorption spectra.
7. Define: Photon
8. What is the chemical composition of the sun?

2. 9. List the seven spectral classes of stars.
10. What color corresponds to spectral class O? M?
11. What do star colors represent?
12. List three types of space motions.
13. A star’s wavelengths exhibit a ____________ if the star is moving away from us. If the star is
moving towards us, its wavelengths exhibit a ____________.
14. Define: Doppler Shift
15. What star motion will change the appearance of the constellations many thousands of years from
now?
16. Define: Luminosity
17. What law governs the propagation of light?

3. 18. Which magnitude scale measures a star’s true luminosity?
19. Which magnitude scale do observers of the night sky use?
20. If a star is located 10 parsecs from earth, its ____________ magnitude and ____________
magnitude would be the same.
21. Describe the Hertzprung-Russell diagram
22. Demonstrate the placement of
the following stars on the H-R
Diagram (right):
Main Sequence
The Sun
Blue Giants
Supergiants
Red Giants
White Dwarfs
Red Dwarfs
23. List two well-known double stars.
24. How does a visual binary star differ from an optical double?