Module 8: Groups of Stars

Groupings of stars occur differently in space. These star groupings can be as small as binary star systems, which include two stars, or as large as galaxies, the smallest of which includes at least one thousand stars. In this module, you will explore these groupings from small to large, beginning with the most basic of groupings, the binary star system. Then, you will examine galaxies, which are large groups of stars, dust, and gas. These galaxies are organized based on their shape as it evolves over time. The Milky Way Galaxy consists of more than 200 billion stars. It is also the galaxy which includes the Solar System and the planet Earth. The Milky Way Galaxy is a barred spiral galaxy. Other galaxies can be elliptical, spiral, or irregular.

Finally, you will learn about the study of the universe's formation through cosmology. There is more than one theory about how the universe began, and you will study two of these theories - the Big Bang Theory and the Steady State Theory. In addition, there are several theories about how the universe will develop over time based on its shape.

Getting Started

Check to see how much you already know about groups of stars in this non-graded activity. Read the instructions associated with each question, and select the appropriate response. Then, click SUBMIT to check your answer. Click the interactivity thumbnail, and then click NEXT to get started.

 

Key Vocabulary

To view the definitions for these key vocabulary terms, visit the course glossary.

Big Bang Theory	galaxy	poor cluster
Big Chill	globular cluster	primary star
Big Crunch	halo	rich cluster
binary star system	homogeneity	secondary star
closed universe	irregular galaxy	singularity
cosmology	isotropy	spectroscopic binary
differential rotation	local group	spiral galaxy
disk	Milky Way Galaxy	star cluster
eclipsing binary	nuclear bulge	Steady State Theory
elliptical galaxy	open cluster	universality
flat universe	open universe	visual binary
galactic cannibalism