Extreme Stars

Over the past 200 years, our knowledge of stars has expanded enormously. From seeing myriad dots of different brightnesses, we moved on to measure distances, temperatures, sizes, chemical compositions, even ages, finding stars that dwarf our Sun and are dwarfed by it, some in their youth, others ancient. First published in 2001, Extreme Stars describes the lives of stars from a fascinating perspective. It examines their amazing extremes and results in an engaging overview of stellar evolution, suitable for anyone interested in viewing or studying stars. Ten chapters, generously illustrated throughout, explain the natures of the brightest, the largest, the hottest, the youngest, and so on, ending with a selection of the strangest stars the Universe has to offer. Taken as a whole, the chapters show how stars develop and die and how each extreme turns into another under the inexorable twin forces of time and gravity.

Presents general information about stars and the sun in a question-and-answer format.

Studies on the populations of luminous stars in nearby resolved galaxies have revealed a complex distribution in the luminosity–temperature plane (the HR diagram). The fundamentals of massive star evolution are mostly understood, but the roles of mass loss, episodic mass loss, rotation, and binarity are still in question. Moreover, the final stages of these stars of different masses and their possible relation to each other are not understood. The purpose of this volume is to provide a current review of the different populations of evolved massive stars. The emphasis is on massive stars in the Local Group, the Magellanic Clouds, and the nearby spirals M31 and M33.

From the Moon, Sun, and planets of our Solar System to space exploration, black holes, and dark matter, this completely revised and updated children’s encyclopedia covers all you need to know about the cosmos. The most up-to-date images from space agencies such as NASA and ESA combine with info panels, timelines, interviews, diagrams, and activities you can do at home to help you understand the majesty and wonder of space. Learn about the Space Race, the Apollo Moon Landings, the Voyager craft that first probed the outer planets, the Hubble telescope, and the International Space Station (ISS) – the state-of-the-art laboratory orbiting Earth. Find out about future missions, space tourism, and the latest discoveries in the furthest reaches of our galaxy. Discover how to find constellations and where to look for stars and planets, including Venus and Mars, in the night sky. Learn how galaxies such as our Milky Way were formed. Part of a series of best-selling encyclopedias for children, Space: A Children’s Encyclopedia is a rocket ride from the beginning of time to the near future, and from planet Earth out to the furthest reaches of the Universe.

In this fascinating Journey to the farther reaches of space, astronomer James Kaler explores the nature of stars, describing their origins, varieties, distributions, compositions, and distinctive histories. He demonstrates that stars are the key to our comprehension of how the universe evolved--and that the birth, development, and death of stars is intimately associated with our own origins. From the earliest folklore to recent theories about dark matter, Stars chronicles the science of stellar astronomy, concluding with the evolution of high mass stars, whose spectacular deaths generate supernovae, pulsars, neutron stars, and enigmatic black holes. Elegantly written and illustrated, Stars is a compelling portrait of the cosmos as a vast engine of regeneration where stars are born, live, and die.

Massive stars occupy an exceptional place in general astrophysics. They trigger many if not all of the important processes in galactic evolution whereas due to their intrinsic brightness, they offer the (only until now) possibility to study the stellar content and stellar behaviour in distant galaxies. The last, say, 25 years, massive stars have been the subject of numerous meetings discussing the influence of massive stars on population synthesis, the number distribution of different types of massive stars, the LBV phenomenon, WR stars, X-ray binaries, stellar winds in massive stars, chemical pecularities in massive stars, supernova explosions of massive stars and the important SN1987A event, the influence of massive stars and chemical evolution of galaxies. It is clear that without a theory of stellar evolution, the study of these topics loses a lot of its significance. Massive star evolution therefore got a chance in these meetings, but rarely as a prime subject. The state of the art, the physical processes and the uncertainties in stellar evolution were barely touched. Even more, the influence of close binaries in all these massive star meetings slowly disappeared the last, say, 13 years without any scientific justification, although a significant fraction of stars occurs in close binaries with periods small enough so that both components will interact during their evolution. Denying the binaries or not discussing their influence on results and conclusions, makes the latter very uncertain or even completely unreliable.

It is sometimes said that astronomy is the crossroads of physics. In the same spirit, it can forcefully be argued that galaxies are the crossroads of astronomy. Internal pro ces ses within galaxies involve all of the fundamental components of astrophysics: stellar evolution, star formation, low-density astrophysics, dynamics, hydrodynamics, and high-energy astrophysics. Indeed, one can hardly name an observational datum in any wavelength range on any kind of celestial object that does not provide a useful clue to galaxy formation and evolution. Although internal processes in galaxies until recently occupied most of our attention, we now know that it is also vital to relate galaxies to their environment. How galaxies congregate in larger structures and are in turn influenced by them are crucial questions for galactic evolution. On a grander level we have also come to regard galaxies as the basic building blocks of the universe, the basic units whereby the large scale structure of the universe is apprehended and quantified. On a grander level still, we also believe strongly that galaxies are the direct descendents of early density irregularities in the Big Bang. Galaxy properties are now viewed as providing a crucial constraint on the physics of the Big Bang and a vital link between the macroscopic and microscopic structure of the universe.