Short answers: Use another sheet if necessary and staple it to your homework.

1. What is the source of energy in the sun?
 
 

2. What are two ways energy is transported from the core to the atmosphere?
 
 

3. Most of the light we see coming from the sun originates in what part of the sun?
 
 

4. What are the three parts of the solar atmosphere?
 
 

5. Why is the corona hotter than the photosphere?
 
 
 
 

6. What is differential rotation and what causes it?
 
 

7. What is the difference between a solar flare and a prominence?
 
 

8. What is the source of the solar wind?
 
 

9. What is a sunspot and how is it formed? Why are they dark?
 
 

10. What is the solar cycle and what does it have to do with the magnetic poles of the sun?
 
 

11. What is the difference between apparent and absolute visual magnitude?
 
 

12. What is parallax used to measure and what are its limitations?
 
 

13. What is intrinsic brightness? What does it mean in terms of energy?
 
 

14. What is luminosity? What does a star's luminosity depend on?
 
 

15. What is an H-R Diagram and what is it a plot of?
 
 

16. Where is the sun in an H-R diagram?
 
 

17. Where on an H-R Diagram are the largest Stars? The smallest?
 
 

18. What is the mass-luminosity relation and what stars obey it?
 
 

19. What is the only direct way of finding the mass of a star? What is an indirect way of finding it?
 
 

20. What is the most common type of star?
 
 

Multiple choice questions.

21. The sun's magnetic field is evident in the looped shapes of

a. solar flares. b. sunspots. c. the corona. d. granules. e. prominences.

22. . The centers of granules

a. are hot material rising to the photosphere from below. b. are cool material falling from the photosphere to the regions below.

23. A ___________ is believed to occur when energy, stored in a twist in the solar magnetic field above a sunspot, is suddenly released. a. solar flare b. supergranule c. spicule d. coronal hole

24. In an H-R Diagram, stars with the smallest radius are found in the _______ of the diagram.

a. center b. upper left corner c. upper right corner d. lower left corner e. lower right corner

25. Compared with the spectral lines in the solar spectrum, lines in a supergiant spectrum are

a. more narrow. b. broader. c. weaker. d. stronger. e. Both broader, and weaker.

26. The most common stars are

a. supergiants. b. giants. c. upper main sequence stars. d. white dwarfs. e. lower main sequence stars.

27. To determine the period of a visual binary, we must measure

a. brightness. b. position. c. wavelengths. d. luminosity. e. temperature.

Use the following HR diagram to answer the next three questions. (28-30)

28. Which star in the diagram above is most like the sun?

a. Alnilam b. Antares c. Arcturus d. HR 5337 e. Sirius B

29. Which star in the diagram above has the greatest surface temperature?

a. Alnilam b. Antares c. Arcturus d. HR 5337 e. Sirius B

30. Which of the stars in the diagram above has the largest absolute visual magnitude?

a. Alnilam b. Antares c. Arcturus d. HR 5337 e. Sirius B

31. In a binary system, the more massive star

a. is at the center of mass. b. is farthest from the center of mass. c. is nearest the center of mass.

d. follows the largest orbit. e. shows a larger Doppler shift in its spectral lines.

32. Which of the following best obey the mass-luminosity relation?

a. main sequence stars b. giant stars c. supergiant stars d. white dwarfs e. all of these

33. Which of the following stars is most dense?

a. a supergiant star b. a main sequence star c. a giant star d. a white dwarf e. the sun

34. A spectroscopic binary shows periodic variations in its

a. radial velocity. b. proper motion. c. brightness. d. mass. e. spectral type.

35. If a star has a parallax of 0.02 seconds of arc, then its distance is

a. 20 pc b. 50 pc c. 2 pc d. 5 pc e. 500 pc