SES4U – Enfield
Astronomy Unit Test – Review Questions:
1. It is true that all the atoms and elements that we currently have on Earth were formed in the
centre of stars. Explain.
2. What is the relationship between a galaxy’s distance to us and it’s speed of recession?
3. How can an astronomer find the distance to a distant galaxy (3 steps)?
4. Why do astronomers want a larger baseline distance when measuring the distance to a star
using the parallax method? What is this distance?
5. What is the distance to a star that shows a parallax of:
a. 0.25 arcsecs?
b. 0.00014 degrees?
6. What is the difference between a reflective telescope and a refractive telescope?
7. What is the advantage of radiotelescopes (i.e. why do we have them)? What is the
disadvantage?
8. What do visible light and radiowaves have in common? What is the difference?
9. How does electromagnetic radiation tell astronomers the following:
a. The temperature of a star?
b. The composition of a star?
c. How far away a distant star is? (3 steps)
10. Which is hotter, a red star or a yellow star?
11. What type of star has low temperature, but high luminosity?
12. Name a constellation that is near the southern horizon this evening at 8:00 pm.
13. Estimate the altitude and azimuth of the constellation named in the previous question.
14. Consider the following two stars and their apparent brightness: Procyon (+0.38), Altair
(+2.38).
a. Which is brighter and by how much?
b. The absolute magnitude of Procyon is +2.66 while that of Altair is +2.22. What does
that imply about the distance of these stars to earth?
15. Describe the evidence of the Big Bang?
16. What is the difference between Doppler red shift and gravitational red shit?
17. What is meant by the term: “observable universe”?
18. If black holes are truly black, how can they even be detected?
19. What is the significance of Olber’s paradox.
20. What is the difference between Newton’s proposal of a gravitational “force” and Einstein’s
theory of general relativity?
21. Why does light bend when it passes near a large star?
Text: p. 872-873 #2-19, 21-28, 31