Part 1

Transcriber’s Notes:

Underscores “” before and after a word or phrase indicate italics_ in the original text. Small capitals have been converted to SOLID capitals. Illustrations and footnotes have been moved so they do not break up paragraphs. Typographical and punctuation errors have been silently corrected.

STARS OF THE SOUTHERN SKIES

STARS OF THE SOUTHERN SKIES

BY M. A. ORR (MRS. JOHN EVERSHED)

AUTHOR OF “AN EASY GUIDE TO SOUTHERN STARS” AND “DANTE AND THE EARLY ASTRONOMERS”

“All experience is an arch wherethrough We glimpse the untravelled world whose margin fades Forever and forever.”

WITH ILLUSTRATIONS

LONGMANS, GREEN AND CO. 39 PATERNOSTER ROW, LONDON FOURTH AVENUE & 30TH STREET, NEW YORK BOMBAY, CALCUTTA, AND MADRAS 1915

All rights reserved

TO MISS MARY PROCTOR

CONTENTS

CHAP. PAGE THE GREEK LETTERS x INTRODUCTION xi I. THE CONSTELLATIONS OF THE SOUTH: MODERN GROUPS 1 II. THE CONSTELLATIONS OF THE SOUTH: ANCIENT GROUPS 6 III. THE TEN BRIGHTEST STARS OF THE SOUTHERN HEMISPHERE 15 IV. STARS OF DIFFERENT AGES 23 V. SOME NEAR NEIGHBOURS 32 VI. DOUBLE AND MULTIPLE STARS 35 VII. THE ASTONISHING STAR, ETA ARGŪS 40 VIII. MIRA, THE WONDERFUL STAR 46 IX. ECLIPSING STARS 51 X. SHORT-PERIOD VARIABLE STARS 54 XI. IRREGULAR AND DOUBTFUL VARIABLES 57 XII. STAR-CLUSTERS 59 XIII. GLOBULAR STAR-CLUSTERS 66 XIV. NEBULAE 72 XV. OTHER TYPES OF NEBULAE 80 XVI. THE CLOUDS OF MAGELLAN 85 XVII. THE MILKY WAY 88

LIST OF ILLUSTRATIONS

PAGE MAP OF THE SOUTHERN HEMISPHERE to face Title

THE OLD CONSTELLATION FIGURES OF THE SOUTHERN HEMISPHERE to face page 6

THE ARCHER page 11 From a Babylonian Boundary Stone now in the British Museum

THE STAR-CLUSTER, 47 TOUCANI to face page 68 From Sir John Herschel’s drawing

THE MILKY WAY IN SCORPIO, LUPUS, AND ARA to face page 88 Photographed at Hanover, Cape Colony, by Bailey and Schultz

THE GREEK LETTERS

α Alpha ν Nu β Beta ξ Xi γ Gamma ο Omicron δ Delta π Pi ε Epsilon ρ Rho ζ Zeta σ Sigma η Eta τ Tau θ Theta υ Upsilon ι Iota φ Phi κ Kappa χ Chi λ Lambda ψ Psi μ Mu ω Omega

INTRODUCTION

This book is for those who have learned or are learning to recognise the southern constellations, but have not read much about astronomy, and have only an opera-glass or small telescope, or no instrument but their own eyes, for examining the stars. I assume that they have studied some simple guide to the constellations like Proctor’s, or my Southern Stars, and that they would like to know something more about the stars they are looking at—how far off they are, how large, if they remain always the same, and if there is any connection between the different parts of this immense universe of stars and nebulae.

I hope that the book will be useful to teachers and parents, helping them to answer some of the searching questions children put, and to teach some of the facts of astronomy in the most vivid and unforgettable way—viz. in connection with special stars and nebulae which are at the moment being admired. If an opera-glass or field-glass can be put into the children’s hands, so that they themselves can see a faint white spot turn into a lovely cluster of stars, it will give them a share in the thrill of discovery, and help them to understand what large telescopes can show.

A map of the southern hemisphere is here given for ready reference, but it would be well to possess a good atlas which gives the letters and numbers assigned to all bright stars and shows the positions of the brightest star-clusters and nebulae. Norton’s Star-Atlas and Telescopic Handbook is an excellent one, small enough to be handy, yet complete as far as it goes, and up to date, clear, and convenient to use.

Published at 5s. by Gall & Inglis, Edinburgh and London.

My intention is to treat specially of stars and nebulae visible in southern countries, so I have confined myself almost entirely to those of the southern hemisphere, though of course many which are north of the celestial equator can be seen also. My readers will find that the southern hemisphere possesses the most beautiful part of the Milky Way, the two brightest stars in the sky, the finest coloured star-cluster and the largest globular cluster, the brightest double star, the nearest of the stars, and the brightest of the large gaseous nebulae. Let us add that the southern hemisphere has been less studied than the north, and therefore there is an even wider field for amateur workers.

Stars of the Southern Skies