About This Chapter
The Milky Way Galaxy - Chapter Summary and Learning Objectives
The lessons in this chapter are designed to provide you with an up-close tour of our own Milky Way galaxy. Gain an understanding of the typical parts of a galaxy, how galaxies are formed, and how they function. Learn about key astronomical concepts like nucleosynthesis and period-luminosity relation. By the time you complete this chapter, you should be able to:
- Discuss the nucleus and other major parts of a galaxy
- Explain why the Milky Way has 'arms'
- Demonstrate your understanding of dark matter
- Understand the difference between population I and II stars
- Define galactic mass
|Galaxy Formation: Spiral, Elliptical, and Irregular Galaxies||Learn how galaxies are formed by type.|
|The Formation of the Milky Way Galaxy||Describe the origins of the Milky Way.|
|The Structure of our Galaxy||Learn about the astronomical parts that make up the Milky Way.|
|The Nucleus of a Galaxy||Identify the nucleus and the activity that occurs here.|
|The Spiral Arms of the Milky Way Galaxy||Provide an evidence-based explanation for why the Milky Way has spiral arms.|
|Population I and Population II Stars||Describe the contours of the Milky Way. Discuss the origins and location of our solar system and how it moves. Provide a brief definition for the following terms: population I and II stars, instability strips, kiloparsecs, nucleosynthesis and period-luminosity relation.|
|The Mass of Our Galaxy||Highlight the differences between the Milky Way galaxy's disk and halo. Demonstrate your understanding of dark matter, including its location.|
1. Galaxy Formation: Spiral, Elliptical & Irregular Galaxies
This lesson explains how galaxies form, starting with the Big Bang. You'll also learn about the solar nebula hypothesis and three galaxy types, including spiral, elliptical, and irregular galaxies.
2. The Formation of the Milky Way Galaxy
This lesson will explore two hypotheses as to how the Milky Way galaxy formed. These are the top-down and bottom-up hypotheses. We'll also go into what special connection you personally have to all of this.
3. How Our Galaxy Was Discovered
This lesson will outline for you the basics of how the galaxy you live in, the Milky Way Galaxy, was discovered over time. You'll also learn about RR Lyrae and Cepheid variable stars.
4. The Structure of Our Galaxy
If you ever looked up at the night sky far away from city lights, you would've seen a band of light across the night sky and lots of stars scattered around the rest of the sky. Why? The structure of our galaxy will explain exactly why.
5. The Nucleus of a Galaxy
This lesson will explore our galaxy's nucleus. Namely, we will find out how we can peer inside using radio waves and infrared, and what that and X-rays tell us about the cool thing that's located inside of it.
6. The Spiral Arms of the Milky Way Galaxy
How do we know our galaxy has spiral arms? You can't really see them, but we can infer they're there thanks to radio waves and observations of other galaxies, which you will learn about in this lesson.
7. Density Wave Theory & Spiral Galaxies
This lesson will teach you about the spiral arms of the galaxy: namely, the major theory that tries to explain their existence as well as why the spiral arms look so different in various kinds of spiral galaxies.
8. Population I and Population II Stars
This lesson will explore the different populations of stars in our galaxy, including population I and II stars, as well as where you can find them and what metals are to an astronomer.
9. The Mass of Our Galaxy
This lessons explores the estimates and numbers surrounding the mass of the Milky Way Galaxy and how they relate to Keplerian motion, the galactic corona, and dark matter.
Earning College Credit
Did you know… We have over 79 college courses that prepare you to earn credit by exam that is accepted by over 2,000 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.
To learn more, visit our Earning Credit Page
Transferring credit to the school of your choice
Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.
Other chapters within the Astronomy 101: Intro to Astronomy course
- The History of Astronomy
- How Scientists Think and Work
- Matter in Astronomy
- Light in Astronomy
- Newton's Laws in Astronomy
- Momentum, Energy, Pressure, Temperature & Gas
- Rotational Motion in Physics
- Earth's Spheres and Astronomy
- Influences on Climate
- The Orbits of Celestial Bodies
- The Earth, Sky, and Moon
- The Moon: Formation & Phases
- The Atmosphere on Earth and Other Planets
- The Sun's Structure & Components
- The Solar System: Layout, Formation & Dating
- Characteristics of Our Solar System's Planets
- Small Celestial Bodies & Satellites in Our Solar System
- Measurement of Star Qualities
- Star Types and Significance
- The Birth and Life of Stars
- Star Death and Stellar Remnants
- Galaxies: Properties & Characteristics
- The Universe: Key Concepts & Theories
- Life in the Universe
- Celestial Navigation & Timekeeping
- Relativity in Time and Space