This NATO Advanced Study Institute provided an up dated understanding, from a fundamental and deep point of view, of the progress and current problems in the early universe, cosmic microwave background radiation, large scale structure, dark matter problem, and the interplay between them. The focus was placed on the Cosmic Microwave Background Radiation. Emphasis was given to the mutual impact of fundamental physics and cosmology, both at theoretical and experimental-or observational-levels, within a deep and well defined programme, and a global unifying view, which, in addition, provides of careful inter-disciplinarity. Special Lectures were devoted to neutrinos in astrophysics and high energy astrophysics. In addition, each Course of this series, introduced and promoted topics or subjects, which, although not being of purely astrophysical or cosmological nature, were of relevant physical interest for astrophysics and cosmology. Deep understanding, clarification, synthesis, careful interdisciplinarity within a fundamental physics framework, werethe maingoals ofthe course. Lectures ranged from a motivation and pedagogical introduction for students and participants not directly working in the field to the latest developmentsand most recent results. All Lectures were plenary, had the same duration and were followed by a discussion. The Course brought together experimentalists and theoretical physicists, astrophysicists and astronomers from a variety of backgrounds, including young scientists at post-doctoral level, senior scientists and advanced graduatestudentsas well.

The symposium on "Neutral Clouds near HII Regions" was prompted by an obvious need to bring together workers specifically interested in the dynamical and photochemical effects in regions showing clear evidence of on-going star formation. This is currently an are a of considerable research activity with much new observational material over the wavelength range from X-ray to radio. Furthermore, the field isbeginning to mature. No longer is molecular spectroscopy concerned only with the search for new lines and with preliminary surveys. No longer are evolving HII regions modelled with the naive assumption of constant density. Similarly, ideas of successive star formation, "champagne" and "blister" models of HII regions, and refinements to abundance calculations are examples which show that theoretical initiative is keeping pace. We were both surprised and gratified by the number of contributed papers and the extent to which they addressed the subject matter. In the proceedings we have grouped these papers near the most appropriate of the four invited review papers. The subjects of these reviews are in the general areas of "Evolution of HII Regions," "Dynamical Interactions," "Chemistry in Active Regions" and "Infrared and Maser Sources." The symposium comprised 42 orally presented papers and 23 poster papers. AII but two are reproduced in this volume.

The progress of science during the past centuries has been in some measure energized by the development of new technologies. People are no more intelligent now than they were five centuries ago, or indeed five millenia ago. The differences are in the pool of past experience and the availability of means for manipulating the physical and mental environment. Until fairly recently, the development of new technologies in astronomy and geodesy has served primarily either to broaden the scope of phenomena that could be studied or to improve the precision with which one could examine already-studied phenomena. There seemed to be no likelihood that a situation could arise similar to that in particle physics, where the uncertainty principle indicates that the observation of the state of an object alters that state, affecting the observation. Indeed, we have not yet reached that point, but certain of the new techniques have introduced a degree of complication and inter dependence perhaps not previously encountered in the macro sciences. When observational capability is so fine that the data can be corrupted by the tidal motions of the instruments, for example, then there are a myriad of physical effects that must be considered in analyzing the data; the happy aspect of this is that the data can be used to study exactly these same effects. The complication does not, however, extend only to predictive computations against which the data are compared."

Viewed as a flashpoint of the Scientific Revolution, early modern astronomy witnessed a virtual explosion of ideas about the nature and structure of the world. This study explores these theories in a variety of intellectual settings, challenging our view of modern science as a straightforward successor to Aristotelian natural philosophy. It shows how astronomers dealt with celestial novelties by deploying old ideas in new ways and identifying more subtle notions of cosmic rationality. Beginning with the celestial spheres of Peurbach and ending with the evolutionary implications of the new star Mira Ceti, it surveys a pivotal phase in our understanding of the universe as a place of constant change that confirmed deeper patterns of cosmic order and stability.

In recent years, it has become clear that the red-giant phase is one of the most dramatic periods in a star's life, when all of its parts become involved in ways that have both direct and indirect observational consequences. This is most particularly true of low- and intermediate mass stars during the second ascent of the giant branch. Such stars bring to their surfaces products of nucleosynthesis currently taking place in their deep interiors, they pulsate as Mira variables, develop extended outward-flowing atmospheres that may exhibit maser properties, and shed great quantities of matter, sometimes highly processed, into the inter stellar medium. The manner in which processed matter is brought to the surface is far from being completely explained, and the precise mechanism or mechanisms whereby matter is ejected from the stellar surface (whether by deposition of Alfven waves, radiation pressure on grains, or as a consequence of so me large scale envelope instability) has yet to be elucidated to every one's satisfaction. The purpose of the second workshop in Astrophysics, organized by the "Advanced School of Astronomy," was to bring together experts on all the physical processes occurring in red giants in an effort to emphasize the interrelatedness of these individual processes, and to encourage a dia logue among experts that might serve to initiate a synthesis, or at least sharpen our understanding of the most important problems to address in the future."

This book records our current understanding of the observational and theoretical properties of objects known as ultracool dwarfs. It covers the state of the art in this new field. It is split into theoretical, observational and spectral classification sections. Each subject area begins with an introduction by an eminent scientist. It covers a wide range of issues, such as the transition from L to T dwarfs, dust and alkali metal modelling, companions, activity, the deuterium test, and brown dwarf variability, and contains considerable discussion about spectral classification schemes. The articles arose from an IAU meeting and they address researchers as well as graduate students.

This classic text, aimed at senior undergraduates and beginning graduate students in physics and astronomy, presents a wide range of astrophysical concepts in sufficient depth to give the reader a quantitative understanding of the subject. Emphasizing physical concepts, the book outlines cosmic events, but does not portray them in detail - it provides a series of astrophysical sketches. For this third edition, nearly every part of the text has been reconsidered and rewritten; new sections have been added to cover recent developments, and most of the rest has been revised and brought up to date. The book begins with an outline of the scope of modern astrophysics and the elementary problems concerning the scale of cosmic objects and events. The basic physics needed to answer these questions is developed in the next chapters, using specific astronomical processes as examples. The second half of the book enlarges on the topics introduced at the beginning and shows how we can obtain quantitative insights into the structure and evolution of stars, the dynamics of cosmic gases, the large-scale behavior of the universe, and the origins of life. supernovae, comets, quasars) are mentioned throughout the text whenever the relevant physics is discussed rather than in individual sections. To compensate, there is an appendix that gives a brief background of astronomical concepts for students unfamiliar with astronomical terminology, as well as a comprehensive index. The extensive bibliography refers to other sources that treat individual topics in detail.

Starting in 1995 numerical modeling of the Earth's dynamo has ourished with remarkable success. Direct numerical simulation of convection-driven MHD- ow in a rotating spherical shell show magnetic elds that resemble the geomagnetic eld in many respects: they are dominated by the axial dipole of approximately the right strength, they show spatial power spectra similar to that of Earth, and the magnetic eld morphology and the temporal var- tion of the eld resembles that of the geomagnetic eld (Christensen and Wicht 2007). Some models show stochastic dipole reversals whose details agree with what has been inferred from paleomagnetic data (Glatzmaier and Roberts 1995; Kutzner and Christensen 2002; Wicht 2005). While these models represent direct numerical simulations of the fundamental MHD equations without parameterized induction effects, they do not match actual pla- tary conditions in a number of respects. Speci cally, they rotate too slowly, are much less turbulent, and use a viscosity and thermal diffusivity that is far too large in comparison to magnetic diffusivity. Because of these discrepancies, the success of geodynamo models may seem surprising. In order to better understand the extent to which the models are applicable to planetary dynamos, scaling laws that relate basic properties of the dynamo to the fundamental control parameters play an important role. In recent years rst attempts have been made to derive such scaling laws from a set of numerical simulations that span the accessible parameter space (Christensen and Tilgner 2004; Christensen and Aubert 2006).

This publication is a result of three meetings, each 5 days long, held at the Goddard Space Flight Center on January 24-28, 1983, June 8-14, 1983, and February 13-17, 1984. The meetings were held in the interim between the full operations of the Solar Maximum Mission (SMM) in 1980, and the renewed operations after its repair in orbit in April 1984. Their general objectives were as follows: o Synthesize flare studies after three years of SMM data analysis. Many analyses of individual flares and individual phenomena, often jointly across many data sources had been published, but a need existed for a broader synthesis and updating of our understanding of solar flares since the Skylab Flare Workshops held several years earlier. o Encourage a broader participation in the SMM data anlysis and combine this more fully with theory and other data sources--data obtained with other spacecraft such as the HINOTORI, P78-1, and ISEE-3 spacecrafts, and with the Very Large Array (VLA) and many other ground-based instruments. Many coordinated data sets, unprecedented in their breadth of coverage and multiplicity of sources, had been obtained within the structure of the Solar Maximum Year (SMY). o Stimulate joint studies, and publication in the general scientific literature. The intended primary benefit was for informal collaborations to be started or broadened at the Workshops with subsequent publications. o Provide a special publication resulting from this Workshop. o Provide a starting point of understanding for planning renewed full observations with the repaired SMM.

This book provides overviews of the new reduction as well as on the use of the Hipparcos data in a variety of astrophysical implementations. A range of new results are included. The Hipparcos data provide a unique opportunity for the study of satellite dynamics as the orbit covered a wide range of altitudes, showing in detail the different torques acting on the satellite. The book is accompanied by a DVD with the new catalogue and the underlying data.

Comet nuclei are the most primitive bodies in the solar system. They have been created far away from the early Sun and their material properties have been altered the least since their formation. Thus, the composition and structure of comet nuclei provide the best information about the chemical and thermodynamic conditions in the nebula from which our solar system formed. In this volume, cometary experts review a broad spectrum of ideas and conclusions based on in situ measurement of Comet Halley and remote sensing observations of the recent bright Comets Hale-Bopp and Hyakutake. The chemical character of comet nuclei suggests many close similarities with the composition of interstellar clouds. It also suggests material mixing from the inner solar nebula and challenges the importance of the accretion shock in the outer nebula. The book is intended to serve as a guide for researchers and graduate students working in the field of planetology and solar system exploration. Several special indexes focus the reader's attention to detailed results and discussions. It concludes with recommendations for laboratory investigations and for advanced modeling of comets, the solar nebula, and the collapse of interstellar clouds.

Our conference - opening today - has two aims in view: first, to commemorate some milestones in the development of the studies of close binary systems whose anniversaries fall in these years, as well as to take stock of our present knowledge accumulated through out preceding decades, in order to consider where do we go from here. This summer, 310 years will have elapsed since the first ec lipsing binary - Algol - was discovered in Bologna by Geminiano Montanari (1633-1687) to be a variable star; and 198 years have gone by since John Goodricke of York (1764-1786) established the fact that Algol's light changes were periodic. Moreover, it is al most exactly (to a month) now 100 years since Edward Charles Pickering (1846-1919) of Harvard Observatory in the United States took the first steps towards the development of systematic methods of analysis of the light changes of Algol and related systems - a topic which will constitute the major part of the programme of our present conference. The three dates recalled above illustrate that the discoverers of such celestial objects and observers of their light changes have been systematically ahead of the theoreticians endea vouring to understand the significance of the observed data by de cades and centuries in the past - a fact which, incidentally, con tinues to hold good (albeit with a diminishing lead-time) up to the present."

The book gives an extended review of theoretical and observational aspects of neutron star physics. With masses comparable to that of the Sun and radii of about ten kilometres, neutron stars are the densest stars in the Universe. This book describes all layers of neutron stars, from the surface to the core, with the emphasis on their structure and equation of state. Theories of dense matter are reviewed, and used to construct neutron star models. Hypothetical strange quark stars and possible exotic phases in neutron star cores are also discussed. Also covered are the effects of strong magnetic fields in neutron star envelopes and a comparison on neutron star models with observations.

This book is based partly on a. lecture course given at the University of Tri este, but mostly on my own research experience in the field of galactic chemical evolution. The subject of galactic chemical evolution was started and developed by Beat rice Tinsley in the seventies and now is a flourishing subject. This book is dedi cated to the chemical evolution of our Galaxy and aims at giving an up-to-date review of what we have learned since Tinsley's pioneering efforts. At the time of writing, in fact, books of this kind were not available with the exception of the excellent book by Bernard Pagel on "Nucleosynthesis and Chemical Evolution of Galaxies" (Cambridge University Press, 1997), and the subject of galactic chem ical evolution has appeared only as short chapters in books devoted to other subjects. Therefore, I felt that a book of this kind could be useful. The book summarizes the observational facts which allow us to reconstruct the chemical history of our Galaxy, in particular the abundances in stars and in terstellar medium; in the last decade, a great deal of observational work, mostly abundance determinations in stars in the solar vicinity, has shed light on the pro duction and distribution of chemical elements. Even more recently more abun dance data have accumulated for external galaxies at both low and high redshift, thus providing precious information on the chemical evolution of different types of galaxies and on the early stages of galaxy evolution."

Astronomy, especially naked-eye astronomy, is a wonderful way for children and young people to engage with the world and universe around them. Many children quickly become fascinated with stars, planets and comets, learning skills that also help them develop generally. This book is a perfect introduction to astronomy for any child, whether or not they have a telescope. It explains the visible constellations and then explores the sun, moon, planets, comets and meteorites. Colour illustrations and diagrams at every stage help children relate what they are reading to what they can see in the sky. Suitable for budding astronomers in both the northern and southern hemispheres, and in polar, temperate or tropical latitudes (i.e., everywhere), this is an ideal introduction the wonders of stargazing.

The 10th ESLAB Symposium was held at Grossenzersdorf near Vienna on 10-13 June 1975 under the title 'The Scientific Satellite Programme During the Inter national Magnetospheric Study'. The Symposium was attended by an invited audience of 60 scientists from the ESA Member States, the United States, Japan, Canada and Austria. Following a report by the joint COSPAR-IUCSTP Special Working Group, the International Magnetospheric Study (lMS) is proposed as an international co operative enterprise of limited duration, having as its principal objective the achie vement of a comprehensive, quantitative understanding of the dynamical processes operating in the Earth's plasma and field environment. In order to accomplish this objective, it is thought to be necessary to carry out simultaneous measurements with nearly identical instrumentation at various points in space. These measurements will need to be made in combination with appropriate observations at or near the Earth's surface. Besides near-Earth observations by ground-based, rocket- and balloon-borne instrumentation, satellite investigations are expected to make an important contri bution to the IMS. A number of satellites assigned to magnetospheric research have recently been launched, or will be launched shortly, to be operational during the IMS. The European Space Agency has devoted two of its forthcoming scientific satellites - GEOS and ISEE-B - to magnetospheric and interplanetary research.

All theoretical and observational topics relevant to the understanding of the thermonuclear (Type Ia) supernova phenomenon are thoroughly and consistently reviewed by a panel including the foremost experts in the field. The book covers all aspects, ranging from the observations of SNe Ia at all stages and all wavelengths to the 2D and 3D modelling of thermonuclear flames in very dense plasmas. Scenarios for close binary evolution leading to SNe Ia are discussed. Particular emphasis is placed on the homogeneity vs. diversity of SNe Ia and on their use as standard candles to measure cosmological parameters. The book reflects the recent and very significant progress made in both the modelling of the explosions and in the observational field.

Even before the present Administrator of NASA, Daniel Goldin, made the phrase 'better, faster, cheaper' the slogan of at least the Office of Space Science, that same office under the Associate Administrator of Lennard Fisk and its Division of Solar System Exploration under the direction of Wes Huntress had begun a series of planetary spacecraft whose developmental cost, phase CID in the parlance of the trade, was to be held to under $150M. In order to get the program underway rapidly they chose two missions without the open solicitation now the hallmark of the program. One of these two missions, JPL' s Mars Pathfinder, was to be a technology demonstration mission with little immediate science return that would enable later high priority science missions to Mars. Many of the science investigations that were included had significant foreign contributions to keep NASA's cost of the mission within the Discovery budget. The second of these missions and the first to be launched was the Near Earth Asteroid Rendezvous mission, or NEAR, awarded to Johns Hopkins University's Applied Physics Laboratory. This mission was quite different than Mars Pathfinder, being taken from the list of high priority objectives of the science community and emphasizing the science return and not the technology development of the mission. This mission was also to prove to be well under the $150M phase CID cap.

Proceedings of IAU Symposium No. 95 held in Bonn, Federal Republic of Germany, 26-29 August 1980

IAU Symposium No. 121 was hosted by the Byurakan Astrophysical Observatory in Soviet Armenia, almost 30 years after Ambartsumian's pioneering ideas about galaxy activity were first published and almost exactly 20 years after the first Byurakan IAU symposium on nuclear activity (No. 29, "Non-stable Phenomena in Galaxies, May 1966). Although the proceedings of the first Byurakan symposium were not published in English, that conference provided a definitive impulse to the field, as Ambartsumian's ideas had done 10 years earlier. The Byurakan Astrophysical Observatory was thus a particularly appropriate setting for IAU 121. The symposium was also very timely since many new exciting results were presented which will surely revolutionize many of our present ideas about nuclear activity in galaxies and QSO's. The first results of the by now famous Markarian survey were presented by B.E. Markarian in the first Byurakan conference. Unfortunately, his untimely death prevented him from attending the second conference, but the influence of his fundamental work was certainly felt.

This book, in three parts, describes three phases in the development of the modern theory and calculation of the Moon's motion. Part I explains the crisis in lunar theory in the 1870s that led G.W. Hill to lay a new foundation for an analytic solution, a preliminary orbit he called the "variational curve." Part II is devoted to E.W. Brown's completion of the new theory as a series of successive perturbations of Hill's variational curve. Part III describes the revolutionary developments in time-measurement and the determination of Earth-Moon and Earth-planet distances that led to the replacement of the Hill Brown theory in 1984.

Leo Goldberg Kitt Peak National Observatory Tucson, Arizona 85726, U. S. A. Of all the reasons for exploring the Universe, none is more com pelling than the possibility of discovering intelligent life elsewhere in the Universe. Still the quest for extraterrestrial life has been near the bottom of the astronomers' list of priorities, not because the number of extraterrestrial civilizations is conjectured to be van ishingly small, but because our powers of detection were thought to be far too weak. About ten years ago, however, the growing reach of ra dio telescopes on the ground and of optical and infrared telescopes in space persuaded a number of thoughtful astronomers that the time for a more serious search had arrived. Accordingly, a joint Soviet-American conference on the problems of Communication with Extraterrestrial In telligence was convened at the Byurakan Astrophysical Observatory of the Armenian Academy of Sciences during September 5-11, 1971 and was soon followed by a number of other important meetings, notably a series of NASA-sponsored workshops in the USA held between January, 1975 and May, 1976. Since SETI is fundamentally an international undertaking and as tronomical methods and techniques are required for its pursuit, it is natural for the International Astronomical Union to lend its support by sponsoring conferences and otherwise facilitating cooperation among countries. The active involvement of the I. A. U."