Module 7: Stars

Twinkle, twinkle, little star,
How I wonder what you are.
Up above the world so high,
Like a diamond in the sky.
Twinkle, twinkle, little star.
How I wonder what you are.
How I wonder what you are.

"Twinkle, Twinkle, Little Star"
by Jane Taylor

It is likely that you are extremely familiar with the lyrics in the song shown above. From the early days of human history and into modern times, humans have wondered about the stars in the night sky. Explorers have set sail by them, artists have painted them, and stars have been an important symbol in the history of the United States, including the American flag. But stars are more than just a symbol or a piece of artistry. These complex structures play an important role in the universe.

In this module, you will explore the characteristics of stars, including their life cycle. You will begin by studying the relationship between mass and luminosity, or the total amount of radiation emitted by a star, and how it impacts the stability of star. In addition, you will learn how stars are measured on the Hertzsprung-Russell (H-R) diagram based on the temperature and luminosity of the stars. Then, you will learn about the two main ways used to find the distance to stars and other celestial objects. Finally, you will look at the life of a star from its birth to its drama-filled ending.

Getting Started

Before you begin your journey through the stars, check to see if you already know some of the terms and concepts that you will learn in this module by completing this interactivity. Read each definition and drag and drop the correct term into the blank provided. Then, click SUBMIT to check your answer. Click the player to get started.

 

Key Vocabulary

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

absolute magnitude	event horizon	parallax
accretion disk	fusion	parsec
apparent magnitude	Hertzsprung-Russell diagram	protostar
astronomical unit (AU)	hydrostatic equilibrium	red giant
binary star	interstellar gas cloud	reflection nebula
brown/black dwarf	luminosity	singularity
black hole	main sequence	spectral classes
Chandrasekhar limit	mass-luminosity relationship	spectroscopic parallax
distance modulus equation	nebula	supernova
emission nebula	neutron star	white dwarf