Until around ten years ago, the only planets that we knew about were within the Solar System. The first genuine planet beyond the confines of the Solar System was discovered only 1988. Since then another 350 or so exoplanets have been detected by various methods, and most of these haven been found in the last ten years. Although many more exoplanets discoveries may be expected to occur even as this book is being read, a large enough data set is now available to form the basis for an informed general account of exoplanets.
The topic hence is an extremely "hot" one - all the more so because the recently launched Kepler spacecraft should soon start uncovering many more exoplanets, some perhaps comparable with the Earth (and therefore possibly alternative homes for mankind, if we could ever reach them). Exoplanets: Finding, Exploring, and Understanding Alien Life gives a comprehensive, balances, and above all accurate account of exoplanets.
The aim of this book is to provide an up-to-date account of active galaxies that is appropriate to the background knowledge of amateur astronomers, but might also be picked-up and read for interest by any reader with a scientific bent.
Active galaxies (including Quasars, QSOs, Radio galaxies, BL Lacs, Blazars, LINERS, ULIRGS, Seyfert galaxies, Starburst galaxies, N galaxies, etc.) are a major field of current astronomical research. Up to a fifth of all research astronomers are working on active galaxies. Huge amounts of time on major telescopes are devoted to their study. In almost all cases the galaxies are thought to be powered by 100 million solar mass black holes at their centres.
Some of the objects are bright enough to be seen in small telescopes, and an amateur astronomer with a 20 cm telescope and a CCD detector could obtain images of many more. Lists of such objects, and their visual and imaged appearance in commercially available telescopes are an important component of this book. This detailed but accessible work will be the only coherent and complete source of information for non-technical readers on an area of astronomy that fascinates many people and whose spectacular images from the Hubble space telescope, Gemini, VLT and other major telescopes frequently make the pages of the quality newspapers and occasionally appear on TV.
It also has the potential to be chosen as a set text or background reading for university courses on the subject, althought he writing style is such that it will appeal to all readers.
As in earlier editions, the author aims to reduce the trend towards fragmentation of astronomical studies. The underlying unity of all of astronomical observation is emphasized by the layout of the book: the pattern of detection → imaging → ancillary techniques has been adopted so that one stage of an observation is encountered together with the similar stages required for all other information carriers.
The book is written in a very accessible manner, and most of the mathematics is accessible to those who have attended a mathematics course in their final years at school. Nevertheless, the treatment of the topics in general is at a sufficiently high level to be of use to those professionals seeking technical information in areas of astronomy with which they might not be completely familiar.