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
- SECTION I COMETS PHYSICALLY CONSIDERED
- SECTION II COMETARY NUCLEI, TAILS, AND COMÆ
- SECTION III COMETS DEVOID OF NUCLEUS AND TAIL
- SECTION IV DIRECTION OF THE TAILS OF COMETS
- SECTION V NUMBER OF TAILS
- SECTION VI DIFFERENT FORMS OF TAILS
- SECTION VII LENGTH OF TAILS
- SECTION VIII FORMATION AND DEVELOPMENT OF TAILS
- SECTION IX BRILLIANCY OF COMETS
- SECTION X DIMENSIONS OF NUCLEI AND TAILS
- CHAPTER VIII PHYSICAL TRANSFORMATIONS OF COMETS
- CHAPTER IX MASS AND DENSITY OF COMETS
- CHAPTER X THE LIGHT OF COMETS
- 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 VIII - FORMATION AND DEVELOPMENT OF 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
- SECTION I COMETS PHYSICALLY CONSIDERED
- SECTION II COMETARY NUCLEI, TAILS, AND COMÆ
- SECTION III COMETS DEVOID OF NUCLEUS AND TAIL
- SECTION IV DIRECTION OF THE TAILS OF COMETS
- SECTION V NUMBER OF TAILS
- SECTION VI DIFFERENT FORMS OF TAILS
- SECTION VII LENGTH OF TAILS
- SECTION VIII FORMATION AND DEVELOPMENT OF TAILS
- SECTION IX BRILLIANCY OF COMETS
- SECTION X DIMENSIONS OF NUCLEI AND TAILS
- CHAPTER VIII PHYSICAL TRANSFORMATIONS OF COMETS
- CHAPTER IX MASS AND DENSITY OF COMETS
- CHAPTER X THE LIGHT OF COMETS
- 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
Variations of length in the tail of Halley's comet at its different apparitions– Similar phenomena exhibited by Donati's comet in 1858–Does the maximum development of the tail always coincide with the perihelion passage of the comet?
It is now desirable to consider a phenomenon of high importance as regards the physical constitution of comets, viz., the development and variation of their tails according to the position which the comet occupies in its orbit; that is to say, according to its greater or less distance from the sun.
It has been already seen that the tails of comets frequently are formed and developed during the period of the comet's visibility, and generally before the perihelion passage. ‘ It has been constantly observed, ’ says Pingré, ‘ that a comet advancing to its perihelion begins to assume a tail only on its near approach to the sun. The fine comet of 1680 had no tail on the 14th of November, thirty-four days before its perihelion passage. The real length of the tail increases day by day, and the head, or rather the coma surrounding the head, seems, on the contrary, to diminish. The tail attains its greatest length shortly after the comet has passed its perihelion; it then diminishes by degrees, but in such wise that at equal distances from the perihelion the tail is longer after the perihelion passage than before. It has been, moreover, observed that comets whose perihelion distance has much exceeded the mean distance of the sun from the earth have not developed tails, and that the tails of others, all else being the same, have been more magnificent in proportion as the perihelion distances have been less.’
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- Information
- The World of Comets , pp. 224 - 231Publisher: Cambridge University PressPrint publication year: 2010First published in: 1877