Naked-eye comets are far from uncommon. As a rough average, one appears every 18 months or thereabouts, and it is not very unusual to see more than two in a single year. The record so far seems to have been 2004, with a total of five comets visible without optical aid. But 2006, 1970, and 1911 were not far behind with a total of four apiece. Yet, the majority of these pass unnoticed by the general public. Most simply look like fuzzy stars with tails that are either faint or below the naked-eye threshold. The classical comet a bright star-like object with a long flowing tail is a sight that graces our skies about once per decade, on average. These great comets are surely among the most beautiful objects that we can see in the heavens, and it is no wonder that they created such fear in earlier times. Just what makes a comet great is not easy to define. It is neither just about brightness nor only a matter of size. Some comets can sport prodigiously long tails and yet not be regarded as great. Others can become very bright, but hardly anyone other than a handful of enthusiastic astronomers will ever see them. Much depends on their separation from the Sun, the intensity of the tail, and so forth.
Naked-eye comets are far from uncommon. As a rough average, one appears every 18 months or thereabouts, and it is not very unusual to see more than two in a single year. The record so far seems to have been 2004, with a total of five comets visible without optical aid. But 2006, 1970, and 1911 were not far behind with a total of four apiece. Yet, the majority of these pass unnoticed by the general public. Most simply look like fuzzy stars with tails that are either faint or below the naked-eye threshold. The classical comet a bright star-like object with a long flowing tail is a sight that graces our skies about once per decade, on average. These great comets are surely among the most beautiful objects that we can see in the heavens, and it is no wonder that they created such fear in earlier times. Just what makes a comet great is not easy to define. It is neither just about brightness nor only a matter of size. Some comets can sport prodigiously long tails and yet not be regarded as great. Others can become very bright, but hardly anyone other than a handful of enthusiastic astronomers will ever see them. Much depends on their separation from the Sun, the intensity of the tail, and so forth.
Über den Autor
David A.J. Seargent holds an MA and PhD, both in Philosophy, from the University of Newcastle NSW, where he formerly worked as a tutor in Philosophy for the Department of Community Programmes/Workers' Educational Association external education programme. He is also a keen amateur astronomer, and is known for his observations of comets, one of which he discovered in 1978. Together with his wife Meg, David lives at The Entrance, north of Sydney on the Central Coast of New South Wales, Australia. He is the author of two astronomy books: Comets: Vagabonds of Space (Doubleday, 1982), and The Greatest Comets in History: Broom Stars & Celestial Scimitars (Springer, 2008). Currently he is the author of a regular column in Australian Sky & Telescope magazine.
Zusammenfassung
Written for astronomers of all levels - from interested "armchair" astronomers to professionals and History of Astronomy students
Gathers together descriptive information on major historical comets that is not readily available elsewhere
Gives a good comparison between recent comets and their older counterparts
Contains a wealth of interesting facts not found in regular astronomy books
Inhaltsverzeichnis
The Nature of Comets.- Halley#x2019;s Comet Through the Ages.- The Greatest Comets of Ancient Times.- The Greatest Comets from A.D. 1000 to 1800.- The Greatest Comets from 1800 to Present Times.- Kamikaze Comets: The Kreutz Sungrazers.- Daylight Comets.
