Extreme Stars: At the Edge of Creation

by James Kaler
2001
hardcover - 236 pages
from Cambridge University Press

Stars, as I tell school children, are like people. People come in different colors and sizes, yet we are all basically the same. Stars come in different colors and sizes as well, even though they all work the same way. That gets across a basic concept, the physics of all stars is the same, but, of course, it vastly oversimplifies the situation. Even though all true stars work on the same principles as our Sun, the physical range of stars truly beggars the imagination. Our Sun is about 860,000 miles across, big enough to fit 1,300,000 Earths inside. Yet there are stars big enough to encompass our solar system out to the orbit of Saturn and fit ten billion (not million) of our Suns inside! Other stars are small enough to fit inside central Los Angeles. Some stars are ten to forty million times brighter than our Sun, while most are so faint that you'd need 100,000 of them to equal the light output of our Sun.

In an age when "extreme sports" and "extreme makeovers" seem all the rage, University of Illinois astronomy professor James Kaler has used these extreme stars to help us better understand how stars work and what the limits of the "stellar envelope" are. Extreme Stars: At the Edge of Creation is a fascinating look at the biggest and smallest, the brightest and faintest, the hottest and coolest, the youngest and oldest, and just plain strangest stars we know.

Last year I highlighted Kaler's more recent The Hundred Greatest Stars, a more grab-bag and popular approach for beginners to the same topic. While Extreme Stars is more demanding than his other book, it is also more organized with fuller explanations and, therefore, more rewarding to the persistent reader. You'll be amazed by the exotic extreme stars Kaler introduces, but also come away with a clearer understanding of why there are limits to how big and how small, as well as how hot and how cool, a star can be. You'll come to realize why a simple look into the night sky can thrill the knowledgeable amateur astronomer. For the stars are not just pretty, yet unchanging, pinpricks of light. They are huge, seething cauldrons of nuclear fury living tumultuous and complex lives, obeying the universal laws of physics, yet balanced precariously on the brink of cosmic destruction. Extreme Stars will leave you better appreciating both those "superstars" of the night sky and that run of that mill, workaday star, we all depend on, our humble Sun.