21^st Century Astronomy, Second Edition

Chapter 19: The Milky Way—A Normal Spiral Galaxy

Study Plan

Of the hundreds of billions of galaxies in the universe, the one that means the most to us is our cosmic home, the Milky Way. The Milky Way may be just another galaxy, but it is the only galaxy we can study at close range. As we focus our attention on our galaxy we will learn

• How variable stars in globular clusters are used as standard candles, allowing us to measure the size of the Milky Way.
• How Doppler-shifted radio emission from gas throughout the rotating disk of the Milky Way allows us to map the galaxy's structure.
• That the Milky Way is a typical giant barred spiral galaxy, and like all such galaxies, it is composed mostly of dark matter.
• How the chemical composition of the Milky Way has evolved with time.
• What differences in age and chemical composition of groups of stars tell us about the history of star formation in our galaxy.
• About the environment within the disk of the Milky Way, and the halo of stars, globular clusters, and dark matter that surrounds our galaxy.
• About the black hole at the center of our galaxy.

Organize

1. Read Chapter 19 in your textbook or ebook.
2. Take the Diagnostic Quiz to assess your understanding of the basic concepts and identify gaps in your understanding of the assigned reading.

Learn

1. Use the FlashCards to test your memory for new terms.
2. Review Extrusions Box 19.1 on Nightfall and Box 19.2 on Searching for Dark Matter in the Halo.
3. Work the "Thinking about the Concepts" and "Applying the Concepts" questions in the end of chapter review materials.
4. If your instructor has assigned SmartWork online homework, login from the right navigation pane for additional practice and review.

Connect

1. Periodic Connections boxes and the Seeing the Forest through the Trees section at the chapter's end draw your attention to recurring themes and help prepare you for concepts explored more fully in subsequent chapters.
2. Visit Astronomy in the News for breaking news of new discoveries and the opportunity to apply what you've learned in this chapter to real-world (and real Universe) events.

Instructors now have an easy way to collect students’ online quizzes with the Norton Gradebook without flooding their inboxes with e-mails.

Students can track their online quiz scores by setting up their own Student Gradebook.