The Sun is an ordinary star. T h e Last In c h Nuclear reactions First hominids make energy. e n Earth Moon h li c n e-i n O e n Tthhee BDiga rBk aAngge h wahden al li o Imagine the history of the Universe cooled and before G as a time line down the middle of an stars began to shine American football field. The story Ten thousand years ago, on begins on one goal line as the Big Formation of the the 0.0026 inch line, humans Bang fills the Universe with first galaxies begin building cities and energy and a fantastically hot gas well under way modern civilization begins. of hydrogen and helium. Follow The Age of Quasars: Galaxies, the history from the first inch of including our home galaxy, actively the time line as the expansion forming, colliding, and merging Formation of the Solar of the Universe cools the gas System, including the Sun and it begins to form galaxies and Earth, from a cloud of and stars. interstellar gas and dust Life begins in Earth’s oceans. Cambrian explosion 540 million years ago: Life in Earth’s oceans becomes complex. The expansion of the Universe stops slowing and begins accelerating. Life first emerges onto the land. e Over billions of years, generation n Age of Dinosaurs al li after generation of stars have lived o and died, cooking the hydrogen G and helium of the big bang into the e atoms of which you are made. n h li Study the last inch of the time line to c see the rise of human ancestors and n e-i the origin of civilization. Only in the n last flicker of a moment on the time O line have humans begun to understand the story. Recombination: A few hundred thousand years after the Big Bang, the gas becomes transparent to light. Anglo-Australian Observatory/David Malin Images h T c heFirst In A typical galaxy contains 100 billion stars. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. The Sun is an ordinary star. T h e LastIn c h Nuclear reactions First hominids make energy. e n Earth Moon h li c n e-i n O e n Tthhee BDiga rBk aAngge h wahden al li o Imagine the history of the Universe cooled and before G as a time line down the middle of an stars began to shine American football field. The story Ten thousand years ago, on begins on one goal line as the Big Formation of the the 0.0026 inch line, humans Bang fills the Universe with first galaxies begin building cities and energy and a fantastically hot gas well under way modern civilization begins. of hydrogen and helium. Follow The Age of Quasars: Galaxies, the history from the first inch of including our home galaxy, actively the time line as the expansion forming, colliding, and merging Formation of the Solar of the Universe cools the gas System, including the Sun and it begins to form galaxies and Earth, from a cloud of and stars. interstellar gas and dust Life begins in Earth’s oceans. Cambrian explosion 540 million years ago: Life in Earth’s oceans becomes complex. The expansion of the Life first emerges onto the land. e Over billions of years, generation n Age of Dinosaurs al li after generation of stars have lived o and died, cooking the hydrogen G and helium of the big bang into the e atoms of which you are made. n h li Study the last inch of the time line to c see the rise of human ancestors and n e-i the origin of civilization. Only in the n last flicker of a moment on the time O line have humans begun to understand the story. Recombination: A few hundred thousand years after the Big Bang, the gas becomes transparent to light. h T c he First In A typical galaxy contains 100 billion stars. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. FSotaurns daantdio ns oGfa Alasxtireosnomy Ftoeunrtth e e n t h eeddiittiioonn MMiicchhaaeell AA.. SSeeeeddss JJoosseepphh R R. .G Grruunnddyy O Obbsseerrvvaattoorryy FFrraannkklilnin a anndd M Maarrsshhaalll lC Coollleleggee DDaannaa EE.. BBaacckkmmaann SSOEFTIIA In (sSttirtauttoes p&h NeAriScA O Abisrebrovranteo r y foArs tIrnofrnaoremdy A Asmtrobnaossmady)ors SSEOTFI IIAns (tSitturateto &sp NhAeSriAc OAmbseesr v atory Rfeosr eInarfcrahr eCde nAtsetrronomy) Australia ● Brazil ● Mexico ● Singapore ● United Kingdom ● United States Australia ● Brazil ● Mexico ● Singapore ● United Kingdom ● United States Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. This is an electronic version of the print textbook. Due to electronic rights restrictions, some third party content may be suppressed. Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. The publisher reserves the right to remove content from this title at any time if subsequent rights restrictions require it. For valuable information on pricing, previous editions, changes to current editions, and alternate formats, please visit www.cengage.com/highered to search by ISBN#, author, title, or keyword for materials in your areas of interest. Important Notice: Media content referenced within the product description or the product text may not be available in the eBook version. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. Stars and Galaxies, Tenth Edition © 2019, 2016, 2013 Cengage Learning, Inc. Michael A. Seeds, Dana E. Backman WCN: 02-300 Unless otherwise noted, all content is © Cengage. Product Director: Dawn Giovanniello Product Manager: Rebecca Berardy Schwartz ALL RIGHTS RESERVED. No part of this work covered by the copyright herein may be reproduced or distributed in any form or by any means, except as permitted by U.S. Content Developer: Rebecca Heider copyright law, without the prior written permission of the copyright owner. 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Intellectual Property Project Manager: Erika Mugavin Library of Congress Control Number: 2017945322 Photo Researcher: Geeta Kamath, Lumina Datamatics Softbound Edition: Text Researcher: Karthick Govindaraju ISBN: 978-1-337-39994-4 Text and Cover Designer: tani hasegawa, tt eye Cover and Title Page Image: Mission:Hubble Loose-leaf Edition: Space Telescope (HST); target:Stephan’s Quintet ISBN: 978-1-337-40010-7 or galaxies NGC 7319,NGC 7318B and NGC 7318A; spacecraft:Hubble Space Telescope; Cengage instrument:Wide Field Planetary Camera 2. 20 Channel Center Street NASA, Jayanne English (University of Manitoba), Boston, MA 02210 Sally Hunsberger (Pennsylvania State University), USA Zolt Levay (Space Telescope Science Institute), Sarah Gallagher (Pennsylvania State University), Cengage is a leading provider of customized learning solutions with employees residing and Jane Charlton in nearly 40 different countries and sales in more than 125 countries around the world.Find your local representative at www.cengage.com. Compositor: MPS Limited Cengage products are represented in Canada by Nelson Education, Ltd. To learn more about Cengage platforms and services, visit www.cengage.com. To register or access your online learning solution or purchase materials for your course, visit www.cengagebrain.com. Printed in the United States of America Print Number: 01 Print Year: 2017 Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. Dedication In memory of Edward & Antonette Backman and Emery & Helen Seeds Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. BriEf ContEntS PArt 1: ExPloring thE Sky PArt 3: thE UnivErSE 1 Here and Now 1 15 The Milky Way Galaxy 310 2 A User’s Guide to the Sky 11 16 Galaxies 335 3 Moon Phases and Eclipses 32 17 Active Galaxies and Supermassive Black Holes 361 4 Origins of Modern Astronomy 52 18 Modern Cosmology 377 5 Gravity 78 6 Light and Telescopes 101 PArt 4: lifE 19 Astrobiology: Life on Other Worlds 408 PArt 2: thE StArS 7 Atoms and Spectra 127 8 The Sun 143 9 The Family of Stars 170 10 The Interstellar Medium 199 11 The Formation and Structure of Stars 216 12 Stellar Evolution 238 13 The Deaths of Stars 262 14 Neutron Stars and Black Holes 286 iv Brief Contents Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. ContEntS PArt 1: ExPloring thE Sky 1 Here and Now 1 how Do wE know? 1-1 Where Are We? 2 1-1 The Scientific Method 8 1-2 When Is Now? 6 1-3 Why Study Astronomy? 7 2-1 Scientific Models 17 2-2 Pseudoscience 26 2 A User’s Guide to the Sky 11 2-3 Scientific Arguments 28 2-1 Stars and Constellations 12 3-1 Scientific Imagination 39 2-2 The Sky and Celestial Motions 17 4-1 Scientific Revolutions 64 2-3 Sun and Planets 21 2-4 Astronomical Influences on Earth’s Climate 25 4-2 Hypotheses, Theories, and Laws 69 5-1 Cause and Effect 83 3 Moon Phases and Eclipses 32 5-2 Testing a Hypothesis by Prediction 92 3-1 The Changeable Moon 33 6-1 Resolution and Precision 109 3-2 Lunar Eclipses 36 3-3 Solar Eclipses 38 3-4 Predicting Eclipses 45 ConCEPt Art 4 Origins of Modern Astronomy 52 The Sky Around You 18–19 4-1 Roots of Astronomy 53 The Cycle of the Seasons 22–23 4-2 The Copernican Revolution 58 4-3 Tycho, Kepler, and Planetary Motion 64 The Phases of the Moon 34–35 4-4 Galileo’s Conclusive Evidence 70 4-5 Ninety-Nine Years That Revolutionized Astronomy 74 An Ancient Model of the Universe 60–61 orbits 86–87 5 Gravity 78 Modern optical Telescopes 112–113 5-1 Galileo’s and Newton’s Two New Sciences 79 5-2 orbital Motion and Tides 84 5-3 Einstein and Relativity 92 6 Light and Telescopes 101 6-1 Radiation: Information from Space 102 6-2 Telescopes 105 6-3 observatories on Earth: optical and Radio 110 6-4 Airborne and Space observatories 116 6-5 Astronomical Instruments and Techniques 118 6-6 Non-Electromagnetic Astronomy 123 Contents v Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.