Astronomy: A Self-Teaching GuideCh. 06: Galaxies

1. Define : Galaxy

2. What is the name of our galaxy and how many stars does it contain?

3. Describe the shape of the Milky Way.

Use the above diagram for the next three questions:

4. How far is the sun from the Milky Way’s center?

5. What is the galaxy’s diameter in light years?

6. When viewed from the side, what objects surround the galaxy in a halo?

7. Fill in the cluster summary table:Open Cluster Globular Cluster

Stars

Locations w.r.t MW

Ages

8. How can the age of a cluster be determined from an H-R diagram of its stars?

9. What is dark matter and how does it affect galaxies?

10. List two components of the interstellar medium.

11. What types of interstellar molecules have been discovered?

12. Compare emission nebulas and dark nebulas.

Emission Dark

13. What might the nucleus of our galaxy contain?

14. Compare Population I and II stars in terms of temperature, luminosity, location in the galaxy, and age.

Population I Population IITemperature

Composition

Location

Age

15. What main types of objects are cataloged in the NGC and Messier lists?

16. What is the age of our galaxy? Of the universe?

17. The universe contains an estimated ____________________ galaxies. Each of these galaxies

contains about ____________________.

18. What are three types of standard candles? What are they useful for?

19. List four of our neighbor galaxies. What are the collectively named?

20. Complete the galaxy table:

Elliptical Spiral IrregularTypes

Morphology

Star ages

21. What are galaxy clusters? What is our galaxy cluster named?

22. What are the Magellanic Clouds?

23. On the largest scale, what does the structure of our universe resemble?

24. What are active galaxies and quasars?