Stars and galaxies

482 Pages·49.958 MB·English

by  Michael A Seeds, Dana E Backman

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About the Authors
Mike Seeds has been a Professor of Physics and Astronomy at Franklin and
Marshall College in Lancaster, Pennsylvania, since 1970. In 1989 he received
F&M College’s Lindback Award for Distinguished Teaching. Mike’s love for the
history of astronomy led him to create upper-level courses on
“Archaeoastronomy” and “Changing Concepts of the Universe.” His research
interests focus on variable stars and the automation of astronomical tele-
scopes. Mike is coauthor with Dana Backman of Horizons: Exploring the
Universe, Eleventh Edition (2009), Astronomy: The Solar System and Beyond,
Sixth Edition (2009), and Perspectives on Astronomy (2008), all published by
Cengage. He was Senior Consultant for creation of the 20-episode telecourse
accompanying the book Horizons, Exploring the Universe.
Dana Backman taught in the physics and astronomy department at Franklin
and Marshall College in Lancaster, Pennsylvania, from 1991 until 2003. He
invented and taught a course titled “Life in the Universe” in F&M’s interdisci-
plinary Foundations program. Dana now teaches introductory astronomy,
astrobiology, and cosmology courses in Stanford University’s Continuing
Studies Program. His research interests focus on infrared observations of
planet formation, models of debris disks around nearby stars, and evolution of
the solar system’s Kuiper belt. Dana is employed by the SETI Institute of
Mountain View, California as Director of Outreach for the SOFIA (Stratospheric
Observatory for Infrared Astronomy) mission at NASA Ames Research Center. He
is coauthor with Mike Seeds of Horizons: Exploring the Universe, Eleventh
Edition (2009), Astronomy: The Solar System and Beyond, Sixth Edition (2009),
and Perspectives on Astronomy (2008), all published by Cengage.
7
S E V E N T H E D I T I O N
Michael A. Seeds
Joseph R. Grundy Observatory
Franklin and Marshall College
Dana E. Backman
SOFIA (Stratospheric Observatory
for Infrared Astronomy)
SETI Institute & NASA Ames
Research Center
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United Kingdom •United States
Stars and Galaxies, Seventh Edition © 2011, 2008, 2007 Brooks/Cole, Cengage Learning
Michael A. Seeds, Dana E. Backman
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Dedication
For Emery & Helen Seeds and Edward & Antonette Backman
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Part 1 Exploring the Sky
CHAPTER 1 HERE AND NOW 1
CHAPTER 2 THE SKY 11
CHAPTER 3 CYCLES OF THE MOON 31
CHAPTER 4 THE ORIGIN OF MODERN ASTRONOMY 49
CHAPTER 5 GRAVITY 75
CHAPTER 6 LIGHT AND TELESCOPES 98
Part 2 The Stars
CHAPTER 7 ATOMS AND STARLIGHT 122
CHAPTER 8 THE SUN 142
CHAPTER 9 THE FAMILY OF STARS 167
CHAPTER 10 THE INTERSTELLAR MEDIUM 192
CHAPTER 11 THE FORMATION AND STRUCTURE OF STARS 210
CHAPTER 12 STELLAR EVOLUTION 232
CHAPTER 13 THE DEATHS OF STARS 255
CHAPTER 14 NEUTRON STARS AND BLACK HOLES 279
Part 3 The Universe
CHAPTER 15 THE MILKY WAY GALAXY 302
CHAPTER 16 GALAXIES 330
CHAPTER 17 ACTIVE GALAXIES AND SUPERMASSIVE BLACK HOLES 355
CHAPTER 18 MODERN COSMOLOGY 369
Part 4 Life
CHAPTER 19 ASTROBIOLOGY: LIFE ON OTHER WORLDS 397
BRIEF CONTENTS
vii
Part 1: Exploring the Sky
Chapter 1 | Here and Now 1
1-1 WHERE ARE YOU? 2
1-2 WHEN IS NOW? 7 How Do We Know?
1-3 WHY STUDY ASTRONOMY? 7
1-1 The So-Called Scientifi c Method 8
Chapter 2 | The Sky 11 2-1 Scientifi c Models 17
2-1 THE STARS 12 2-2 Pseudoscience 25
2-2 THE SKY AND ITS MOTION 16
2-3 Evidence as the Foundation of Science 27
2-3 THE CYCLES OF THE SUN 20
2-4 Scientifi c Arguments 28
2-4 ASTRONOMICAL INFLUENCES ON EARTH’S CLIMATE 25
3-1 Scientifi c Imagination 38
4-1 Scientifi c Revolutions 61
Chapter 3 | Cycles of the Moon 31
3-1 THE CHANGEABLE MOON 32 4-2 Hypothesis, Theory, and Law 66
3-2 LUNAR ECLIPSES 33 5-1 Cause and Effect 80
3-3 SOLAR ECLIPSES 37 5-2 Testing a Hypothesis by Prediction 89
3-4 PREDICTING ECLIPSES 43 6-1 Resolution and Precision 105
Chapter 4 | The Origin of Modern Astronomy 49
4-1 THE ROOTS OF ASTRONOMY 50
4-2 THE COPERNICAN REVOLUTION 58 Concept Art Portfolios
4-3 PLANETARY MOTION 61
4-4 GALILEO GALILEI 67 The Sky Around You 18–19
4-5 MODERN ASTRONOMY 71 The Cycle of the Seasons 22–23
The Phases of the Moon 34–35
Chapter 5 | Gravity 75
5-1 GALILEO AND NEWTON 76 The Ancient Universe 56–57
5-2 ORBITAL MOTION AND TIDES 82
Orbiting Earth 84–85
5-3 EINSTEIN AND RELATIVITY 90
Modern Astronomical Telescopes 110–111
Chapter 6 | Light and Telescopes 98
6-1 RADIATION: INFORMATION FROM SPACE 99
6-2 OPTICAL TELESCOPES 101
6-3 SPECIAL INSTRUMENTS 112 Focus on Fundamentals 1 | Mass 79
6-4 RADIO TELESCOPES 114 Focus on Fundamentals 2 | Energy 86
6-5 ASTRONOMY FROM SPACE 117
CONTENTS
viii