It's not a tabloid headline, but a simple statement of what stars sometimes do. Kaler's descriptive aptly summarises the theme of this fine work. Astronomy done well is always a fascinating read, and Kaler's done a masterful job. He takes us into the realm of the biggest, hottest, smallest, coolest, most dense and diffuse stars in our universe. Each chapter is devoted to a type, with examples, history, evolution and likely finales. The text is clear and unambiguous, obviously written for anyone interested in our stellar neighbours. Diagrams and photographs illuminate complex subjects throughout, including some spectacular colour plates in one section. Kaler deserves high praise for a comprehensive and exhaustive presentation untainted by weighty philosophy or arcane mathematics.
Kaler's uses the nearest star, our sun, to launch a comparative view of the more extreme versions of stellar objects. Placed in the middle of the band of stars fitting on the "main sequence", it's a valid starting point. Main sequence stars range from very large and bright to very small and dim. Within that range they follow fairly predictable patterns for a given size and type. Outside that stable range, however, loom some immense exceptions and a plethora of tiny, almost minuscule stellar objects. Orion's shoulder is marked by a star with a diameter nearly reaching the orbit of Jupiter. Another, even greater, reach nearly to Saturn's. Others, as Kaler notes, would "fit inside a small town". Even these minute objects have a life history that tells us much about the universe we inhabit. Kaler is vivid in his descriptions of these objects, but he's even more spirited when dealing with the nuclear processes going on within them. Some stars truly seem to "run amok"!
Stars are distant laboratories where reactions occur impossible to duplicate in Earth-bound facilities. Kaler describes the activities of chemical elements within stellar objects and how their signals tell us about the events occurring there. As stars burn away their hydrogen fuel, various options, some still not understood, may be followed. Electrons jump from shell to shell emitting or absorbing energy. These signals, he notes, are the indicators of luminosity, temperature and even distance. One such signal, of course, is the most significant of all - the "noise" indicating the Big Bang that started it all. One result, however, is clear - without these processes neither our planet nor we would exist. This is because the stars, which began as clouds of hydrogen and dust, become the forges of heavier elements. As Joni Mitchell once sang, "we are all made of star stuff". You don't have to be interested in astronomy to enjoy this book. You need only care about your origins and environment. [stephen a. haines - Ottawa, Canada]