The Brightest Stars : Discovering the Universe Through the Sky's Most Brilliant Stars

Fred Schaaf is one of the most experienced astronomical observers of our time. For more than two decades, his view of the sky-what will be visible, when it will be visible, and what it will look like-has encouraged tens of thousands of people to turn their eyes skyward. —David H. Levy, Science Editor, Parade magazine, discoverer of twenty-one comets, and author of Starry Night and Cosmic Discoveries "Fred Schaaf is a poet of the stars. He brings the sky into people's lives in a way that is compelling and his descriptions have all the impact of witnessing the stars on a crystal-clear dark night." —William Sheehan, coauthor of Mars: The Lure of the Red Planet and The Transits of Venus In this book, you’ll meet the twenty-one brightest stars visible from Earth. You’ll learn how to find these stars and discover the best ways to see them. Each star is profiled in a separate chapter, with detailed guidance on what to look for while observing it. Suitable for beginners as well as experienced amateur astronomers, the book shares fascinating information about the lore and legends connected with each star through history, as well as what the science of astronomy has to teach us about the star’s physical nature. THE BRIGHTEST STARS: Discovering the Universe Through the Sky's Most Brilliant Stars 4 Contents 6 Acknowledgements 8 Introduction 10 Part I: STARS IN THE SKY 14 Chapter 1: HOW BRIGHT IS BRIGHT? 16 A Sky Full of Stars - and Several Questions 16 A Matter of Magnitude 18 Extending the Old Range of Magnitudes 19 Defining 1st Magnitude 20 The Brightest Twenty-One 20 Chapter 2: MEET THE 1ST-MAGNITUDE STARS 22 The 1st-Magnitude Stars of Winter 22 The 1st-Magnitude Stars of Spring 26 A Far-South Digression 28 The 1st-Magnitude Stars of Summer 30 The 1st-Magnitude Star of Autumn - and Winter’s Return 32 Chapter 3: THE LOCATIONS, YEARLY MOTIONS, AND NAMES OF THE STARS 34 Defining Constellations and Asterisms 34 The Seasonal Progression of Constellations 35 The Zodiac Constellations, and Conjunctions 36 Positions in the Sky: Altitude and Azimuth 38 Positions in the Heavens: Declination and Right Ascension 39 Universal Time 41 Measuring Sky Angles with Your Hand 42 Circumpolar Stars 43 Precession and the Succession of North Stars 45 Star Names and Designations 46 Chapter 4: SEEING STARS BETTER (SKIES, EYES, AND TELESCOPE) 48 Light Pollution 48 Transparency and “Seeing” 50 The Phases and Hours of the Moon 51 Dark Adaptation and Averted Vision 53 Binoculars 54 Telescopes and Their Three Key Abilities 55 Basic Types and Parts of Telescopes 56 Part II: STARS IN THE UNIVERSE 58 Chapter 5: PARTS, STRUCTURE, DISTANCES, AND MOTIONS IN THE UNIVERSE 60 The Sun and Its Solar System 60 Stars, Nebulae, and Star Clusters 61 Galaxies and the Universe 64 Interplanetary Versus Interstellar Distances 66 Units of Distance in Astronomy 68 Luminosity and Absolute Magnitude 69 Motions of Stars in Space 70 Chapter 6: THE VARIETIES OF THE STARS 72 Double and Multiple Stars 72 Variable Stars, Novae, and Supernovae 74 The Spectrum of Starlight 76 Spectral Types 77 Luminosity Classes 78 Chapter 7: THE LIVES AND DETHS OF THE STARS 80 How Stars “Burn” Hydrogen 80 The Hertzsprung-Russell Diagram 81 A Star Is Born 83 The Life and Death of a Solar-Mass Star 84 The Life and Death of a Low-Mass and a High-Mass Star 85 Neutron Stars and Black Holes 87 Part III: PROFILES OF THE BRIGHTEST STARS 90 Chapter 8: SIRIUS 92 The Brilliance of Sirius 93 The Scintillation and True Color of Sirius 94 The Heliacal Rising of Sirius 96 The Name Sirius and the Dog Days 99 Sirius and Sirius B as Suns 101 Discovering and Observing Sirius B 104 The Lives of Sirius and Sirius B 105 Red Sirius, the Dogon, and Triple Sirius 106 Sirius in Lore and Culture before the Twentieth Century 107 Sirius in Lore and Culture in the Twentieth and Twenty-First Centuries 109 The View from Sirius 110 The Once and Future Sirius 111 Peerless and Dearest Sirius 113 Chapter 9: CANOPUS 113 Second to Sirius 114 How Far North Is Canopus Visible? 115 "Canopus" as Star, Pilot, and Port 116 Canopus Venerated by the Arabs 117 The Rudder of Lost Argo 119 The Struggle to Find Canopus’s Distance and Luminosity 120 Canopus as a Sun 121 Canopus the Four-Time King 122 The Star to Steer By 123 Chapter 10: ALPHA CENTAURI 124 The Closest Neighbor 125 The Most Spectacular Bright Double 126 The Southern Pointers of Centaurus 128 Little Bit of Lore 130 Far Centaurus and the Ambassador to Peladon 131 Alpha Centauri A and B as Suns 132 Proxima Centauri as a Sun and Flare Star 133 The View from Alpha Centauri 134 Chapter 11: ARCTURUS 135 Spring’s Bright Bear-Guard 135 Bow, Owl, Algon, Hawaii-Finder, Fair-Opener, and Light to Hell 137 Three Great Comets and “the Faire Starre Arcturus” 138 Champagne Shot with Roses 139 Arcturus as a Bright Star and a Sun 140 It Came from Beyond 142 The View from Arcturus 145 Chapter 12: VEGA 145 The Queen Star of Summer 146 Vega in the Summer Triangle 146 Vega in the Telescope 148 Vega as Destination, Pole Star, and Future Brightest Star 148 Vega in Legend and Lore 149 The Possible Planet of Vega 151 The Flattened, Hot-Poled Vega 152 The Pole Star of Vega 154 Chapter 13: CAPELLA 155 Capella’s First-in-Fall Beauty 155 Capella for Christmas 157 A Star for Three Seasons 158 Summer Capella and “the Clouds of Capella” 159 Capella’s Name and Lore 160 Double Capella 162 Yellow Capella 164 Past Capella 164 The View from Capella 165 An Exchange of Side-by-Side Champions 165 Chapter 14: RIGEL 166 Rating Rigel 166 Rigel as a Sun 168 The Foot of Al Jauzah 168 The Companion of Rigel 169 Chapter 15: PROCYON 172 Suffering by Comparison 172 The Lesser Dog Star 172 Before the Dog 174 The Lore of Procyon 176 Procyon A and B as Suns 177 The View from Procyon 178 Chapter 16: ACHERNAR 179 The River’s End 180 Lonely Achernar 180 The Flattest Star 181 More on Achernar as a Sun 182 Chapter 17: BETELGEUSE 183 The Name and Lore of Betelgeuse 183 The Brightest Red Giant 185 The Best Brightness of Betelgeuse 186 How Big Is Betelgeuse? 187 Star within a Star? 190 When Will Betelgeuse Blow? 190 Chapter 18: BETA CENTAURI 191 The Three-Named Partner of Alpha Centauri 191 The Twin Giants of Hadar A 193 Chapter 19: ALPHA CRUCIS 194 The Real Acrux Trio 196 Acrux as Visual Double or Triple 194 Acrux in the Scorpius-Centaurus Association 196 Chapter 20: ALTAIR 197 The Eye of the Eagle 197 Altair in China 199 Noble Positionings of Altair 200 Altair as a Sun 202 The View from Altair 205 Chapter 21: ALDEBARAN 205 The Most Connected Star 206 Occultations of Aldebaran 207 Aldebaran and the Clusters 208 The Lore of Aldebaran 209 Aldebaran in Modern Poetry and Science Fiction 211 The Departing Eye 212 Aldebaran as a Sun 215 The View from Aldebaran 216 The Ultimate Double North Star 216 Chapter 22: SPICA 217 Spica’s Connections with Bright Stars and Constellations 217 Spica and the Diamond of Virgo 219 The Virgin’s Ear of Wheat 219 The Names and Lore of Spica 220 Occultations and Conjunctions of Spica 221 Spica as a Sun - or Suns 223 Chapter 23: ANTARES 224 The Heart of the Scorpion 225 The Rival of Mars 226 The Green Companion of Antares 227 The Rival of Betelgeuse 229 Antares’s Surroundings and the Companion’s Nature 231 Antares in the Scorpius-Centaurus Association 232 The Lore of Antares 232 Chapter 24: POLLUX 233 The Less Acclaimed of the Twins 234 The Planet of Pollux 235 Conjunctions, Occultations, and Color of Pollux 236 The Nearest Giant 237 Chapter 25: FOMALHAUT 239 The Lonely Star 239 The Autumn Star and Lonely Lighthouse 241 Fomalhaut’s Company 242 The Name Fomalhaut and the First Frog 242 Fomalhaut as a Sun 244 Fomalhaut’s “Kuiper Belt” and Possible Planet 244 Fomalhaut’s Fellow Wayfarer 246 Chapter 26: BETA CRUCIS 247 Beta Crucis and the Jewel Box 247 Becrux and the Mystery of Mimosa 248 Beta Crucis as Suns 249 Chapter 27: DENEB 250 The Tail of the Swan 251 How Bright, How Far? 252 Deneb as a Sun 254 Bound for Deneb 255 Chapter 28: REGULUS 256 The Little King 256 Pumpkin, Raindrop, or Bullet 258 A Heart Oft-Visited 261 Appendix A: The Brightest Stars: Postion, Spectral Type, Apperent and Absolute Magnitude, and Distance 264 Appendix B: The Brightest Stars: Spectral Type, Color Index, Color, and Surface Temperature 265 Appendix C: Midnight and 9:00 P.M. Culminations Season of Prime Evening Visibility 266 Appendix D: Diameters and Masses of the Brightest Stars 267 Appendix E: Motions of the Brightest Stars 268 Appendix F: The 200 Brightest Stars 269 Glossary 275 Sources 278 Illustration Credits 281 Index 282 The stars have captivated artists, romantics, sages, and scientists for centuries, inspir-ing countless civilizations as symbols of humanity's highest aspirations. The very word astronomy means "ordering of the stars," and studying these stunning pieces of fire is an ideal way to begin to appreciate the limitless wonders of the sky.In this book, you'll meet the twenty-one brightest stars visible from Earth and discover their remarkable secrets. From Sirius and Alpha Centauri to Rigel and Regulus, you'll learn how to find these stars and the major constellations and discover the best ways to see them. Each star is profiled in a separate chapter, with detailed guidance on what to look for while observing it. There is fascinating information about the lore and legends connected with each star through history, as well as what the science of astronomy has to teach us about the star's physical nature based on exciting discoveries made in the last few years, including new, more accurate data on star distances, mass, and composition.