The present sixth volume of ISSI Space Sciences Series is the outcome of the most ambitious study project of ISSI hitherto, that on 'Source and Loss Processes of Magnetospheric Plasma'. The goal has been to produce a fully integrated book on the subject, which gives an authoritative overview of all aspects of the topic in a well organized form, useful and readable both for active researchers in the field and for young scientists who are starting their research in space physics. In order to represent the full diversity of experience and perspective that exists in the science community, some 50 leading scientists from allover the world were invited to participate in the project and contribute to the text. With the scientific competence well in hand, the dominating problem in producing the book has been to achieve a degree of consistency in style, nomenclature, notations and format, as well as good cross referencing. To what degree we have succeeded in reaching our goal of delivering a volume that will be useful to the community in both its comprehensiveness and readability remains to be decided by the readers. The book is the outcome of a three year long process. In December 1995 the study project on 'Source and Loss Processes of Magnetospheric Plasma' was se lected by ISSI after consultations with several groups of senior representatives of the space physics community."

Beyond the four centuries of sunspot observation and the five decades during which artificial satellites have monitored the Sun that is to say for 99.99999% of the Sun 's existence our knowledge of solar history depends largely on analogy with kindred main sequence stars, on the outcome of various kinds of modelling, and on indirect measures of solar activity. They include the analysis of lunar rocks and meteorites for evidence of solar flares and other components of the solar cosmic-ray (SCR) flux, and the measurement of cosmogenic isotopes in wood, stratified ice and marine sediments to evaluate changes in the galactic cosmic-ray (GCR) flux and thus infer changes in the sheltering magnetic fields of the solar wind. In addition, shifts in the global atmospheric circulation which appear to result from cyclic fluctuations in solar irradiance have left their mark in river sediments and in the isotopic composition of cave deposits. In this volume the results these sources have already produced have been summarised, paying special attention to those that reflect processes in different parts of the Sun 's interior and that display periodicities and trends which may enable us to forecast future large-scale environmental changes.

The most massive stars in the galaxy - those with more than 15 to 20 solar masses - are lilkely to ionize their surroundings before they reach their final mass. How can they accrete in spite of the presence of over-pressurized gas?
This thesis presents results of Submillimeter Array (SMA) and Very Large Array (VLA) studies of massive star formation regions in the early stages of ionization, as well as an analysis of numerical simulations of the evolution of these young HII regions. The results favor a picture in which very massive stars form in accretion flows that are partially ionized and that keep accreting material from their environment.

Theoretical researches in general relativity and observational data from galactic astronomy combine in this volume in contributions to one of the oldest questions of natural philosophy: Is the structure of the physical world more adequately described by a continuous or a discrete mode of representation? Since the days of the Pythagoreans, this question has surfaced from time to time in various guises in science as well as in philosophy. One of the most bitterly contested and illuminating controversies between the continuous and the discrete viewpoints is to be found in the wave versus corpuscular description of optical phenom enae. This controversy was not resolved to the satisfaction of most of its protaganists until the development of the quantum theory. However, several obscurities that still becloud the question suggest that some deeper formulation may be necessary before more satisfactory answers can be given 1. The firm establishment of the validity of quantized structure and discrete energy distributions on the atomic scale following the ideas of Max Planck, together with the apparent absence of quan tization effect in astronomical and cosmic structures leaves uncertainties concerning the role played by the scale of the observer in perceiving or not perceiving discrete distributions. Some of the metaphysical inter pretations and implications of the quantum mechanics that have been made in recent years 2 would be subject to revision if the existence of discretized descriptions were to be established in astronomical and cosmic structures."

Three eminent scientists, each well known for the clarity of their writing, present for students and researchers what is known about the internal structure, origin and evolution of White Dwarfs, Neutron Stars and Black Holes, all objects at the final stage of stellar evolution. They cover fascinating topics such as pulsation of white dwarfs, millisecond pulsars or the dynamics around black holes. The book is written for graduate students in astrophysics, but is also of interest to professional astronomers and physicists.

C. Agostinelli: Sul problema delle aurore boreali e il moto di un corpuscolo elettrizzato in presenza di un dipolo magnetico.- G. Colombo: Introduction to the theory of earth 's motion about its center of mass.- E.M. Gaposchkin: The motion of the pole and the earth 's elasticity as studied from the gravity field of the earth by means of artificial earth satellites.- I.I. Shapiro: Radar astronomy, general relativity, and celestial mechanics.- V. Szebehely: Applications of the restricted problem of three bodies in space research.- G.A. Wilkins: The analysis of the observation of the satellites of Mars.

It may at first seem that the world of subatomic physics is far removed from our every day lives. Isn t it all just a waste of time and taxpayers' money? Hopefully, all who read this book will come to a different conclusion. Collider physics is all about our origins, and this aspect alone makes it worthy of our very best attention. The experiments conducted within the vast collider chambers are at the forefront of humanity s quest to unweave the great tapestry that is the universe. Everything is connected. Within the macrocosm is the microcosm. By knowing how matter is structured, how atoms and elementary particles interact, and what forces control the interactions between the particles, we discover further clues as to why the universe is the way it is, and we uncover glimpses of how everything came into being. The Large Hadron Collider (LHC), in the process of coming online at CERN, is the world s largest and most complex machine. It represents the pinnacle of human ingenuity, and its physical characteristics, costs, and workings astound us at every turn. We are literally humbled by the machine that has been produced through a grand international collaboration of scientists. This book is about what those scientists hope to discover with the LHC, for hopes do run high, and there is much at stake. Careers, reputations and prestigious science prizes will be realized, and possibly lost, in the wake of the results that the LHC will produce. And there are risks, real and imagined. The LHC will probe the very fabric of matter and it will help us understand the very weft and the weave of the universe."

The Foundations of Celestial Reckoning gives the reader direct access to the foundational documents of the tradition of calculation created by astronomers of the early Chinese empire between the late second century BCE and the third century CE. The paradigm they established was to shape East Asian thought and practice in the field of mathematical astronomy for centuries to come. It was in many ways radically different from better known traditions of astronomy in other parts of the ancient world. This book includes full English translations of the first three systems of mathematical astronomy adopted for use by imperial astronomical officials, together with introductory material explaining the origin and nature of each system, and a general introduction to the work as a whole. The translations, which are accompanied by the original Chinese text, give a consistent rendering of all technical terms, and include detailed explanatory notes. The text in which the second of the three systems is found also includes a unique collection of documents compiled around 178 CE by two experts in the field, one of whom was the author of the third system translated in this book. Using material transcribed from government archives of the two preceding centuries, these scholars carefully document and review controversies and large-scale official debates on astronomical matters up to their own time. Nothing equivalent in detail and clarity has survived from any other ancient culture. The availability of the totality of this material in English opens new perspectives to all historians of pre-modern astronomy.

This second volume of a comprehensive three-volume work on theoretical astrophysics deals with stellar physics. After reviewing the key observational results and nomenclature used in stellar astronomy, the book develops a solid understanding of central concepts including stellar structure and evolution, the physics of stellar remnants, pulsars, binary stars, the sun and planetary systems, interstellar medium and globular clusters. Throughout, the reader's comprehension is developed and tested with more than seventy-five exercises. This indispensable volume will allow graduate students to master the material sufficiently to read and engage in research with heightened understanding. It can be used alone or in conjunction with Volume 1, which covers a wide range of astrophysical processes, and the forthcoming Volume 3, on galaxies and cosmology.

Ptolemy's "Almagest" is one of the most influential scientific works in history. A masterpiece of technical exposition, it was the basic textbook of astronomy for more than a thousand years, and still is the main source for our knowledge of ancient astronomy. This translation, based on the standard Greek text of Heiberg, makes the work accessible to English readers in an intelligible and reliable form. It contains numerous corrections derived from medieval Arabic translations and extensive footnotes that take account of the great progress in understanding the work made in this century, due to the discovery of Babylonian records and other researches. It is designed to stand by itself as an interpretation of the original, but it will also be useful as an aid to reading the Greek text.

Large area sky surveys are now a reality in the radio, IR, optical and X-ray passbands. In the next few years, new surveys using optical, UV and IR mosaic cameras with high throughput digital detectors will expand the dynamic range and accuracy of photometry and astrometry of objects over a significant fraction of the entire sky. Parallel X-ray and radio surveys over the same areas will produce astronomical image and spectroscopic databases of unprecedented size and quality. The combined data sets will provide significant new constraints on star formation, stellar dynamics, Galactic structure, the evolution of galaxies and large scale structure, as well as new opportunities to identify rare objects in the solar system and the Galaxy. Large area surveys have formidable data acquisition, processing, archiving, and data distribution demands and this meeting provided a forum for sharing experiences amongst workers specializing in different wavebands as well as discussing how multiband observations can reveal fundamental relationships in our understanding of the Universe.

In the past two decades, scientists have made remarkable progress in understanding stars. This graduate-level textbook provides a systematic, self-contained and lucid introduction to the physical processes and fundamental equations underlying all aspects of stellar astrophysics. The timely volume provides authoritative astronomical discussions as well as rigorous mathematical derivations and illuminating explanations of the physical concepts involved. In addition to traditional topics such as stellar interiors and atmospheres, the reader is introduced to stellar winds, mass accretion, nuclear astrophysics, weak interactions, novae, supernovae, pulsars, neutron stars and black holes. A concise introduction to general relativity is also included. At the end of each chapter, exercises and helpful hints are provided to test and develop the understanding of the student. As the first advanced textbook on stellar astrophysics for nearly three decades, this long-awaited volume provides a thorough introduction for graduate students and an up-to-date review for researchers.

Pulsars, generally accepted to be rotating neutron stars, are dense, neutron-packed remnants of massive stars that blew apart in supernova explosions. They are typically about 10 kilometers across and spin rapidly, often making several hundred rotations per second. Depending on star mass, gravity compresses the matter in the cores of pulsars up to more than ten times the density of ordinary atomic nuclei, thus providing a high-pressure environment in which numerous particle processes, from hyperon population to quark deconfinement to the formation of Boson condensates, may compete with each other. There are theoretical suggestions of even more "exotic" processes inside pulsars, such as the formation of absolutely stable strange quark matter, a configuration of matter even more stable than the most stable atomic nucleus, T56Fe. In the latter event, pulsars would be largely composed of pure quark matter, eventually enveloped in nuclear crust matter. These features combined with the tremendous recent progress in observational radio and x-ray astronomy make pulsars nearly ideal probes for a wide range of physical studies, complementing the quest of the behavior of superdense matter in terrestrial collider experiments. Written by an eminent author, Pulsars as Astrophysical Laboratories for Nuclear and Particle Physics gives a reliable account of the present status of such research, which naturally is to be performed at the interface between nuclear physics, particle physics, and Einstein's theory of relativity.

Over the last few decades inversion concepts have become an integral part of experimental data interpretation in several branches of science. In numerous cases similar inversion-like techniques were developed independently in separate disciplines, sometimes based on different lines of reasoning, but not always to the same level of sophistication.
This book is based on the Interdisciplinary Inversion Conference held at the University of Aarhus, Denmark. For scientists and graduate students in geophysics, astronomy, oceanography, petroleum geology, and geodesy, the book offers a wide variety of examples and theoretical background in the field of inversion techniques.

IAU Symposium No. 167 brought together researchers who use CCDs and arrays, designers and manufacturers of CCDs and Array Mosaics and those who write the software to control these devices and to reduce the large amounts of data contained in each frame. At the meeting such topics as plans for applying the new technology to the new large telescopes that have been built recently and those planned in the near future, new developments in infrared arrays, advances and concerns with the use of CCDs in photometry and spectroscopy and the creation of large mosaics in photometry and spectroscopy and the creation of large mosaics of chips which allow larger areas of the sky to be covered in a single frame were discussed. There were sessions devoted to the following topics: New Developments in CCD Technology; New Developments in IR Detector Arrays; Direct Imaging with CCDs and Other Arrays; Spectroscopy with CCDs and Other Arrays; and Large Field Imaging with Array Mosaics. Scientific results of studies made with this technology were covered in the poster sessions. CCD and Array Detectors have become the detectors of choice at all the world's optical observatories. Such instruments on small university and college telescopes have turned these telescopes into instruments that can now do observations which in the past were done only on the largest telescopes. CCDs and Arrays are known as the people's detector' because of their ability to turn small telescopes into true research instruments. On large telescopes observations can be made of extremely faint and crowded objects that were impossible to observe before the advent of CCD and Array technology. The proceedings of this meeting will be useful toall those who are interested in the design, manufacture and use of CCDs and Arrays for astronomical observations.

The present book represents to a large extent the translation of the German "Vorlesungen uber Himmelsmechanik" by C. L. Siegel. The demand for a new edition and for an English translation gave rise to the present volume which, however, goes beyond a mere translation. To take account of recent work in this field a number of sections have been added, especially in the third chapter which deals with the stability theory. Still, it has not been attempted to give a complete presentation of the subject, and the basic prganization of Siegel's original book has not been altered. The emphasis lies in the development of results and analytic methods which are based on the ideas of H. Poincare, G. D. Birkhoff, A. Liapunov and, as far as Chapter I is concerned, on the work of K. F. Sundman and C. L. Siegel. In recent years the measure-theoretical aspects of mechanics have been revitalized and have led to new results which will not be discussed here. In this connection we refer, in particular, to the interesting book by V. I. Arnold and A. Avez on "Problemes Ergodiques de la Mecanique Classique," which stresses the interaction of ergodic theory and mechanics. We list the points in which the present book differs from the German text. In the first chapter two sections on the tri pie collision in the three body problem have been added by C. L. Siegel."

The 1990s are proving to be a very exciting p&iod for high angular resolution astronomy. At radio wavelengths a combination of new array instruments and pow erful imaging algorithms have generated images of unprecedented resolution and quality. In the optical and infrared, the great technical difficulties associated with constructing separated-aperture interferometers have been largely overcome, and many new instruments are now operating or are being developed. As these pro grams start to produce observational results they will be able to draw extensively on the experience gained by the radio-interferometry community. Thus it seemed that the time was ripe for a meeting which would bring together workers from all wavelength ranges to discuss the details of the science and art of "Very High Angular Resolution Imaging" . While the main emphasis of Symposium No. 158 was on high resolution tech niques from the radio, mm-wave, infrared and optical bands, it also provided an opportunity for presentation of astronomical results from these techniques. As well as giving our colleagues from the Northern Hemisphere a break from midwinter, the location of the Symposium in Australia recognised the continuing development of astronomical interferometry in this country, especially the recent completion of the Australia Telescope radio array, and the progress toward com missioning of the Sydney University Stellar Interferometer. A number of the par ticipants visited these instruments during the post-symposium tour."

The concept of aeroassisting for orbital transfer has been recognized as one of the critical technologies for pioneering the space frontier. In space transportation systems, aeroassisting (or aerobraking), defined as the deceleration resulting from the effects of atmospheric drag upon a vehicle during orbital operations, opens new mission opportunities, especially with regard to the establishment of the permanent Space Station Freedom and space explorations to other planets such as Mars. The main areas of research reported in this monograph are atmospheric entry problem by the method of matched asymptotic expansions, coplanar and non-coplanar orbital transfers with aeroassist technology, orbital plan change with aerocruise, and neighbouring optimal guidance. A special feature is the bibliography which will provide the reader with a literature status for further research.

The author discusses whether time travel is scientifically possible. He examines "the history of the development of general relativity, the conceptof curved space-time and the early evolution of the universe. The remainder of the book seeks to] explain the problems that arise when we attempt to turntheoretical holes in space-time into time machines." (N Y Times Book Review)

The authors discuss such topics as "impacts with asteroids, the greenhouse effect, nuclear winter, fringe catastrophism, supernovae and an assessment of risks." (New Scientist)

The present book is a translation of the original German edition (published in 1982) with some minor corrections and improvements. The guide to sup plementary and advanced literature given in the Appendix, however, has been brought up to date. This book is addressed primarily to students taking astronomy as a prin cipal or subsidiary subject, and to scientists of related fields, but amateur as tronomers should also be able to profit from it. For most chapters an elementary knowledge of mathematics and physics will be sufficient, however, Chaps. 5 and 6 impose somewhat greater requirements. In addition the reader should already be acquainted with the basic concepts of stellar physics as treated in introduc tory books, including the spectral types, the system of stellar magnitudes and colours, absolute magnitudes and luminosities, the Herlzsprung-Russell dia gram and its interpretation. A modem textbook should use SI units. On the other hand, the use of the cgs system is still the prevailing custom in astrophysics - together with the special units of astronomy: length is quoted in parsecs [pc], mass in solar masses [M0] and time in years [a]. We have therefore compromised and employed both cgs and SI units in this book, whichever was the appropriate choice in each instance. A table for conversion of cgs units into SI units and vice versa is given in the Appendix.

Proceedings of the 129th Symposium of the International Astronomical Union, held in Cambridge, MA, USA, May 10-15, 1987