Chapter 16--Properties of Stars

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Astronomy Place Web Tutorials
Tutorial Review of Key Concepts
Use the interactive Tutorials at www.astronomyplace.com to
review key concepts from this chapter.
Hertzsprung–Russell Diagram Tutorial
Lesson 1 The Hertzsprung–Russell (H–R) Diagram
Lesson 2 Determining Stellar Radii
Lesson 3 The Main Sequence
Measuring Cosmic Distances Tutorial
Lesson 2 Stellar Parallax
Stellar Evolution Tutorial
Lesson 1 Main-Sequence Lifetimes
Lesson 4 Cluster Dating
Supplementary Tutorial Exercises
Use the interactive Tutorial Lessons to explore the following
questions.
Hertzsprung–Russell Diagram Tutorial, Lessons 1–3
1. If one star appears brighter than another, can you be sure
that it is more luminous? Why or why not?
2. Answer each part of this question with either high, low,
left, or right. On an H–R diagram, where will a star be if
it is hot? Cool? Bright? Dim?
3. Why is there a relationship between stellar radii and locations
on the H–R diagram?
MEDIA EXPLORATIONS
For a complete list of media resources available, go to www.astronomyplace.com, and choose Chapter 16 from the pull-down menu.
4. Why is there a relationship between luminosity and mass
for main-sequence stars on the H–R diagram?
Measuring Cosmic Distances Tutorial, Lesson 2
1. Explain how we measure distances with stellar parallax.
Give an example.
2. Explain why we cannot use parallax to measure the distance
to all stars.
Stellar Evolution Tutorial, Lesson 4
1. In the animation at the beginning of Lesson 4, list the order
in which you saw the three differently colored stars in the
cluster disappear, and explain why they disappeared in this
order.
2. In the second animation in Lesson 4, in what order did
you see stars on the main sequence disappear? Explain the
reason for this.
3. How does the age of a dim star cluster of mostly small stars
compare to a bright cluster with some giants in it? Explain
your answer.
Voyager: SkyGazer
Exploring the Sky and Solar System
Of the many activities available on the Voyager: SkyGazer CD-
ROM accompanying your book, use the following files to observe
key phenomena covered in this chapter.
Go to the File: Basics folder for the following demonstrations:
1. Large Stars
2. More Stars
3. Star Color and Size
Go to the File: Demo folder for the following demonstrations:
1. Circling the Hyades
2. Flying Around Pleiades
3. The Tail of Scorpius
Web Projects
Take advantage of the useful web links on www.astronomyplace.
com to assist you with the following projects.
1. Women in Astronomy. Until fairly recently, men greatly
outnumbered women in professional astronomy. Nevertheless,
many women made crucial discoveries in astronomy
throughout history. Do some research about the life and
discoveries of a woman astronomer from any time period,
and write a two- to three-page scientific biography.
2. The Hipparcos Mission. The European Space Agency’s Hipparcos
mission, which operated from 1989 to 1993, made
precise parallax measurements for more than 40,000 stars.
Learn about how Hipparcos allowed astronomers to measure
smaller parallax angles than they could from the ground
and how Hipparcos discoveries have affected our knowledge
of the universe. Write a one- to two-page report on your
findings.
chapter 16 • Properties of Stars 543