Star Watch , livre ebook

STAR WATCH
The Amateur Astronomer s Guide to Finding, Observing, and Learning about Over 125 Celestial Objects
Philip S. Harrington

John Wiley Sons, Inc.
This book is printed on acid-free paper.
Copyright 2003 by Philip S. Harrington. All rights reserved
Published by John Wiley Sons, Inc., Hoboken, New Jersey
Published simultaneously in Canada
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Library of Congress Cataloging-in-Publication Data:
Harrington, Philip S.
Star watch : the amateur astronomer s guide to finding, observing, and learning about over 125 celestial objects / Philip S. Harrington.
p. cm.
Includes bibliographical references and index.
ISBN 0-471-41804-8 (pbk. : acid-free paper)
1. Astronomy-Amateurs manuals. 2. Astronomy-Observers manuals. I. Title.
QB63.H319 2003
522-dc21
2003043272
Printed in the United States of America
10 9 8 7 6 5 4 3 2 1
For my niece Lilia, nephew Daniel, and goddaughter Samantha.
In loving memory of Dorothy Harrington (1919-2003).
Contents
Preface
Acknowledgments
1 Your Passport to the Stars
2 The Moon
3 The Planets and Asteroids
4 The Sun
5 The Deep Sky
6 Spring Sky Windows
7 Summer Sky Windows
8 Autumn Sky Windows
9 Winter Sky Windows
Epilogue: Afterthoughts

Appendices
A. The Constellations
B. Planets: 2003-2015
C. The Messier Catalog Plus

Bibliography and References
Glossary
Index
Preface
Astronomy . . . is most impressive where it transcends explanation. It is not the mathematics of astronomy, but the wonder and mystery that seize upon the imagination. The dominion which astronomy has always held over the minds of men is akin to poetry; when the former becomes merely instructive and the latter purely didactic, both lose their power over the imagination. Astronomy is known as the oldest of the sciences, and it will be the longest-lived because it will always have arcana that have not been penetrated.
With those words, Garrett P. Serviss opened his book Curiosities of the Sky. Though published in 1909, those words remain true to this day. The wonder of astronomy is not in the numbers and data that scientists collect and study, but rather in what is behind the numbers: the amazement and curiosity that the objects of the universe generate in our minds. Serviss s book was meant to take the reader to those wonders, to explain what each was, and to demonstrate what the backyard astronomer of the early twentieth century might see through a telescope. To that end, Serviss continued: Some of the things described in this book are little known to the average reader, while others are well known; but all possess the fascination of whatever is strange, marvelous, obscure, or mysterious-magnified, in this case, by the portentous scale of the phenomena. I cannot think of a better way to describe the purpose of this book that you hold before you. We will follow the same path trod by Serviss one hundred years ago, but through the eyes of a twenty-first century astronomer using modern equipment. Wondrous sights, including the Moon, Sun, and planets, star clusters, nebulae, and far-distant galaxies are up there waiting for us, as they have been for millions, even billions, of years.
But the universe is a far different place from what Serviss could have ever imagined. Today, thanks to space probes to the Moon and planets, huge telescopes here on Earth, orbiting astronomical observatories, and advances in optics and electronics, astronomers have uncovered some amazing facts about our universe. As amateur astronomers, we can enjoy many of these same advances, both in knowledge and equipment, allowing us to view sights that Serviss never knew existed.
This book will serve as a guide for you to explore these far-distant objects. Chapter 1 explains some basic astronomical terms that will help orient the newcomer to the sky. Beginning with chapter 2, we launch our trip by taking one small step out to the Moon. In the chapters that follow, our attention will be turned toward the planets, the Sun, and finally the four seasonal skies, each of which holds some outstanding deep-sky objects-objects that lie beyond our solar system-including vast star clusters, glowing nebulae, and distant galaxies. Each target, whether near or far, is discussed both in terms of locating and observing it, as well as in terms of the latest scientific studies and findings. Star Watch gives you over 125 suggested targets for viewing and tells you how to find them, when to view them at their best, and what you can expect to see through both binoculars and telescopes. You ll also find physical descriptions of each object, including size, distance, and structure, as well as scientific explanations of what you are looking at.
Remember, large telescopes are not needed to discover the heavens. Indeed, all of the objects discussed in this book can be spotted through a modest 6-inch telescope; in fact, all but perhaps half a dozen can be viewed through instruments half that size and even through common binoculars. Garrett Serviss would have been amazed!
I welcome your comments about this book, whether they be praise or complaints. Just write to me in care of the publisher, John Wiley Sons, or directly via e-mail at phil@philharrington.net.
Acknowledgments
Several people have been instrumental in creating Star Watch , and it is only proper to acknowledge their contributions and express my gratitude to each in this forum. All the celestial photographs found throughout this book were taken by amateur astronomers. Astrophotography is not easy, and so I must thank those accomplished photographers who graciously allowed me to use some of their work: Jim Fakatselis, Chris Flynn, Brian Kennedy, Richard Sanderson, Gregory Terrance, and George Viscome.
I wish to pass on my sincere appreciation to my astronomical colleagues who read through the manuscript and offered many constructive suggestions: Chris Adamson, Kevin Dixon, Geoff Gaherty, and Richard Sanderson. It is difficult enough to critique a stranger s written word, but when a friend asks you, it can be especially touchy. Just how honest do you want to be? Let me say that each of these readers was both sensitive to my fragile ego, as well as aware that changes were needed to make a better book. You and I are both in debt to them for their ability to balance both needs. Special thanks to Kate Bradford, my editor at John Wiley Sons, for suggesting the idea for this book in the first place, and for her diligent guidance and help.
Finally, my deepest thanks, love, and appreciation go to my ever-patient family. My wife, Wendy, and our daughter, Helen, have continually provided me with boundless love, patience, and encouragement over the years. Were it not for their understanding my need to go out at three in the morning or drive an hour or more from home just to look at the stars, this book could not exist. I love them both dearly for that.
1
Your Passport to the Stars
Since before the dawn of history, our ancestors have gazed skyward in awe and wonder. At first, the universe seemed cold, inhospitable, and filled with danger. Was the sky populated by gods of the Moon, the Sun, and planets who ruled mortals and could destroy or spare Earth with a mere wave of their hands? Did our very lives depend on their whimsy? As time evolved, curiosity grew about the exact nature of the Sun, the Moon, and other sky objects. The ancient Babylonians, Assyrians, and Greeks were among the first civilizations to study the sky in an attempt to understand how these objects influenced the course of human events. Their studies gave birth to the pseudoscience of astrology but more importantly also laid the basic foundation for the science of astronomy. Indeed, many of the names for stars and star patterns, called constellations , that we still use today trace their origin back to this early epoch.
Perhaps the greatest study of the universe by one of our ancient ancestors was performed by the Greek astronomer Claudius