Book contents
- Frontmatter
- EDITOR'S PREFACE
- PREFACE
- Contents
- LIST OF ILLUSTRATIONS
- CHAPTER I BELIEFS AND SUPERSTITIONS RELATIVE TO COMETS
- CHAPTER II COMETARY ASTRONOMY UP TO THE TIME OF NEWTON
- CHAPTER III THE MOTIONS AND ORBITS OF COMETS
- CHAPTER IV PERIODICAL COMETS
- CHAPTER V PERIODICAL COMETS
- CHAPTER VI THE WORLD OF COMETS AND COMETARY SYSTEMS
- CHAPTER VII PHYSICAL AND CHEMICAL CONSTITUTION OF COMETS
- CHAPTER VIII PHYSICAL TRANSFORMATIONS OF COMETS
- CHAPTER IX MASS AND DENSITY OF COMETS
- CHAPTER X THE LIGHT OF COMETS
- SECTION I INTEREST ATTACHING TO THE PHYSICAL STUDY OF COMETARY LIGHT
- SECTION II TRANSPARENCY OF NUCLEI, ATMOSPHERES, AND TAILS
- SECTION III COLOUR OF COMETARY LIGHT
- SECTION IV SUDDEN CHANGES OF BRILLIANCY IN THE LIGHT OF COMETARY TAILS
- SECTION V DO COMETS SHINE BY THEIR OWN OR BY REFLECTED LIGHT?
- SECTION VI SPECTRAL ANALYSIS OF THE LIGHT OF COMETS
- SECTION VII THE COMET OF 1874, OR COGGIA'S COMET
- CHAPTER XI THEORY OF COMETARY PHENOMENA
- CHAPTER XII COMETS AND SHOOTING STARS
- CHAPTER XIII COMETS AND THE EARTH
- CHAPTER XIV PHYSICAL INFLUENCES OF COMETS
- CHAPTER XV SOME QUESTIONS ABOUT COMETS
- I ELLIPTIC ELEMENTS OF THE RECOGNISED PERIODICAL COMETS OF THE SOLAR SYSTEM
- II GENERAL CATALOGUE OF THE ORBITS OF COMETS
- Plate section
SECTION IV - SUDDEN CHANGES OF BRILLIANCY IN THE LIGHT OF COMETARY TAILS
Published online by Cambridge University Press: 05 March 2012
- Frontmatter
- EDITOR'S PREFACE
- PREFACE
- Contents
- LIST OF ILLUSTRATIONS
- CHAPTER I BELIEFS AND SUPERSTITIONS RELATIVE TO COMETS
- CHAPTER II COMETARY ASTRONOMY UP TO THE TIME OF NEWTON
- CHAPTER III THE MOTIONS AND ORBITS OF COMETS
- CHAPTER IV PERIODICAL COMETS
- CHAPTER V PERIODICAL COMETS
- CHAPTER VI THE WORLD OF COMETS AND COMETARY SYSTEMS
- CHAPTER VII PHYSICAL AND CHEMICAL CONSTITUTION OF COMETS
- CHAPTER VIII PHYSICAL TRANSFORMATIONS OF COMETS
- CHAPTER IX MASS AND DENSITY OF COMETS
- CHAPTER X THE LIGHT OF COMETS
- SECTION I INTEREST ATTACHING TO THE PHYSICAL STUDY OF COMETARY LIGHT
- SECTION II TRANSPARENCY OF NUCLEI, ATMOSPHERES, AND TAILS
- SECTION III COLOUR OF COMETARY LIGHT
- SECTION IV SUDDEN CHANGES OF BRILLIANCY IN THE LIGHT OF COMETARY TAILS
- SECTION V DO COMETS SHINE BY THEIR OWN OR BY REFLECTED LIGHT?
- SECTION VI SPECTRAL ANALYSIS OF THE LIGHT OF COMETS
- SECTION VII THE COMET OF 1874, OR COGGIA'S COMET
- CHAPTER XI THEORY OF COMETARY PHENOMENA
- CHAPTER XII COMETS AND SHOOTING STARS
- CHAPTER XIII COMETS AND THE EARTH
- CHAPTER XIV PHYSICAL INFLUENCES OF COMETS
- CHAPTER XV SOME QUESTIONS ABOUT COMETS
- I ELLIPTIC ELEMENTS OF THE RECOGNISED PERIODICAL COMETS OF THE SOLAR SYSTEM
- II GENERAL CATALOGUE OF THE ORBITS OF COMETS
- Plate section
Summary
Rapid undulations occasionally observed in the light of cometary tails ; observations of Kepler, Hevelius, Oysatus, and Pingre; comets of 1607, 1618, 1652, 1661, and 1769–Undulations in the tails of the comets of 1843 and 1860; do these undulations arise from a cause peculiar to the comet itself, or do they depend upon the state of the atmosphere?–Objection made by Olbers to the first of these hypotheses ; refutation by M. Liais.
The tails of certain comets have exhibited variations of brilliancy, sudden changes of intensity, analogous to the phenomena of the same kind which are observed in the aurora borealis, and which, it is believed, have been remarked in the zodiacal light. This fact was unknown to the ancients ; and when Seneca speaks of the augmented or diminished brilliancy of comets, it is evident that he alludes to the changes produced, in the course of their apparition, by the variations of their distance from the earth. He compares them ‘to other stars which throw out more light and appear larger and more luminous in proportion as they descend and come nearer to us, and are smaller and less luminous as they are returning and increasing their distance from us.’ (Quæstiones Naturales, vii. 17.)
Kepler is the first observer who has made mention of these singular changes.
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- The World of Comets , pp. 305 - 308Publisher: Cambridge University PressPrint publication year: 2010First published in: 1877