Astronomy 122
Test 1




NAME _____________________________________________________________________


Multiple Choice Questions -- 30 questions @ 2 points per question ----> 60 points

Select the best answer for each question.



1. The Solar Constant is roughly 1,400 Watts per square meter. of the sphere.

2. Gamma Rays _____ .

3. Of the following parts of the electromagnetic spectrum, which pass freely through the atmosphere of the Earth?

4. A Main Sequence star has luminosity class _____ .

5. Two stars have the same surface temperature. The larger one has a surface area 2 times greater than the smaller one. The larger star radiates how much more energy than does the smaller one?

6. Astronomers know that iron atoms are present in the Sun because _____ .

7. An atom is held together (bound) by ____ .

8. X-rays are _____ than radio waves, _____ radio waves. 9. The change in the appearance of stellar spectra as you move through the spectral sequence is due to _____ .

10. The Sun currently shines because _____ .

11. The luminosity of the Sun _____ the Solar Activity Cycle.

12. The Russell-Vogt Theorem states that the properties of a star are determined primarily by the star's _____ .

13. The primary difference(s) between the spectra of stars in different spectral classes is(are) _____ .

14. The fundamental difference between radio waves and x-rays is that _____ .

15. When the Universe began expanding 13.7 billion years ago, it was made primarily of _______ .

16. The rotation period for the Sun is roughly _____ .
17. By the word spectrum, we mean _______ .

18. The masses of stars on the Main Sequence _____ .

19. The regions in the Hertzsprung-Russell diagram where there are concentrations of stars are _____ .
20. The colors of some glowing bodies are listed below. Which body is the coolest?

21. The most numerous stars in our galaxy are ________ .
22. The determination of stellar parallax is important because it allows the direct determination of _____ .
23. The nucleus of an atom is composed of _____ .

24. Binary star systems are particularly important for _____ .
25. The spectral class which shows the strongest hydrogen lines is _____ .

26. The mass-luminosity relationship for main sequence stars says _____ .
27. The experiments designed to detect Solar neutrinos find that _____ .
28. Early workers in spectroscopy discovered which very significant fact about the spectra produced by hot low-density gases?
29. The spectral type of the Sun is _____ .
30. The most useful probe of the current state of the interior of the Sun _____ .




























Short Answer Questions -- 8 questions @ 5 points per question ----> 40 points




1. What is the Maunder Minimum? Explain how it shows that the climate of the Earth is strongly affected by the behavior of the Sun.





















2. The line, We are stardust from Woodstock by Joni Mitchell, is an apt and scientifically appropriate statement about the chemical make-up of the Earth and us. Explain why the line is a scientifically accurate statement about the chemical make-up of the Earth and us.





















3. M type stars do not show strong hydrogren lines in the visible light portion of their spectra. Is this true because M stars do not contain hydrogen? If this is not true (M stars do in fact contain hydrogen), explain why M stars do not show strong hydrogen lines in their spectra.























4. What is Wien's Law? What is the Stefan-Boltzmann Law? To what kind of object do the Wien Law and Stefan-Boltzmann Law apply, strictly speaking?





















5. Briefly, describe how astronomers determine the surface temperatures of stars using their continuous spectra OR their absorption line spectra. Note--just choose one method to describe.





















6. State Kirchhoff's Three Laws of Spectral Formation. Which of the three laws applies to the formation of the absorption line spectrum observed from most stars?

























7. Sketch a Hertzsprung-Russell (H-R) diagram. Be sure to label the axes and indicate the locations of the Super-giants, normal giants, Main Sequence stars, and white dwarfs. Circle the region in the H-R diagram where the bulk of the observable stars are found.


















































8. Use the energy level diagram for hydrogen to answer the following questions.

i. Which transitions reprensent lines that would fall in the visible part of the spectrum?




ii. Which transitions are Lyman transitions?




iii. Which transition has the smallest energy?




iv. Which transition represents ionization?




v. Draw in an absorption line from the Paschen series of lines.





















Part

Points

Multiple Choice

 

Short Answer

 

Total