Proceedings of IAU Symposium No. 75 held in Geneva, Switzerland, September 6-10, 1976. Dedicated to Solomon Pikel'ner

Accretion disks are ubiquitous in our universe, and produce intense brightening. How does the gas in the disk lose its angular momentum to release massive amounts of gravitational energy? This is one of the biggest open questions in astronomy. This book studies four types of newly detected outbursts in dwarf novae through optical observations and/or numerical simulations and puts forward physical interpretations of these outbursts on the basis of the disk instability model, the most plausible model for dwarf-nova outbursts. It demonstrates that the disk-instability model can explain rich variety in dwarf-nova outbursts if some new aspects are taken into account (e.g. the extremely slow growth of tidal instability and thermal instability in the disk misaligned against the binary orbital plane). Moreover, it shares valuable insights on the evolution of binary systems by finding period bouncers and dwarf novae with F-type companion stars, which are rare objects.

The following topics are addressed: space astrometric missions, ground based optical techniques, very long baseline interferometric (VLBI) techniques, impact of these techniques on astrophysics and on geodynamics, and issues related to celestial and terrestrial reference frames. In the area of space optical astrometry, the reduction of one year of data from the Hipparcos mission shows excellent results for more than 40,000 stars. Recent developments in ground-based optical astrometry are concentrated on CCB meridian circles and transit instruments. The VLBI technique is the most powerful method to determine the earth rotation parameters, nutation series, and baseline lengths. More accurate celestial and terrestrial reference frames are needed and recent achievements in this field are presented, for example FK5 catalogues and a comparison of VLA and Hipparcos positions.

Planetary nebulae are the classic subject of astrophysics. The physical pro cesses occurring in this highly ionized gaseous medium, the formation of emis sion lines in clearly specified conditions, the continuous emission extending from the far ultraviolet up to infrared and radio frequencies, the generation of exotic forms of radiation predicted by atomic physics, along with methods for deciphering the observed spectra and detecting physical and kinematic parameters of the radiating medium, etc. - all these problems form the solid foundations of the physical theory of gaseous nebulae. They are an essential part of the arsenal of powerful tools and concepts without which one cannot imagine understanding and interpreting the enormous diversity of processes taking place in the Universe - in gaseous envelopes surrounding the stars of various classes, from cool dwarfs and flare stars up to hot supergiants, as well as in stellar chromospheres and coronae, in atmospheres of unstable and anomalous stars, in circumstellar clouds and gaseous shells born in nova and supernova explosions, in diffuse nebulae and the interstellar medium, in interacting binary systems, in galaxies with emission lines, in quasars, etc. The last thirty years have seen a turning-point in our knowledge concern ing the very nature of planetary nebulae (PNs). The radio emission of PNs was discovered after it was predicted theoretically. On the other hand, the powerful infrared emission discovered both in the continuum and in emission lines was never expected."

These are the proceedings of an international meeting hosted by the Royal Observatory, Edinburgh, to commemorate the 30th anniversary of the dedication of the UKIRT, the United Kingdom InfraRed Telescope.

The volume comprises 31 professional level papers. The first part of the book has 10 thorough reviews of the conception, design and build of the telescope, as well as accounts of some its key instruments such as IRCAM (the common-user infrared camera), CGS4 (the fourth Cooled Grating Spectrometer) and the Wide Field Camera. The second part of the book comprises 14 reviews of scientific achievements during its twenty years of visitor mode operations. The final part of the book is a series of 7 reviews of the results from the multiple surveys being done as part of UKIDSS (UKIRT Infrared Deep Sky Survey).

The authors are all experts in their respective fields, for example instrument scientists, operations staff and leading astronomers.

Solid particles are followed from their creation through their evolution in the Galaxy to their participation in the formation of solar systems like our own, these being now clearly deduced from observations by the Hubble Space Telescope as well as by IR and visual observations of protostellar disks, like that of the famous Beta Pictoris object. The most recent observational, laboratory and theoretical methods are examined in detail. In our own solar system, studies of meteorites, comets and comet dust reveal many features that follow directly from the interstellar dust from which they formed. The properties of interstellar dust provide possible keys to its origin in comets and asteroids and its ultimate origin in the early solar system. But this is a continuing story: what happens to the solid particles in space after they emerge from stellar sources has important scientific consequences since it ultimately bears on our own origins - the origins of solar systems and, especially, of our own earth and life in the universe.

Interest world-wide in the provision of new observational astro nomical facilities in the form of ground-based optical telescopes of large aperture has never been higher than exists at present. The benefits to be gained from increased aperture size, however, are only utilised effectively if efficient instrumentation is also available. There have been significant improvements recently in this area, part icularly in detector technology and data handling as well as in optical design, so that systems which are currently being developed have the capability of being vastly more powerful in terms of the efficient use of photons than those which existed only 5 years ago. The rationale for the decision by Commission 9 of the International Astronomical Union to hold IAU Colloquium 67, therefore, was to obtain reports on these developments with the emphasis placed upon overall efficiency of the complete observational system - from telescope aperture right through to detector output. A fitting venue for the meeting was the site of the 6 metre BTA (Bolshoi Azimuth Telescope) at Zelenchukskaya in the Caucasus mount ains, USSR. The BTA is operated by the Special Astrophysical Observatory located at Nizhnij Arkhyz, a few kilometres from the telescope itself."

Europa The Ocean Moon tells the story of the Galileo spacecraft probe to Jupiter's moon, Europa. It provides a detailed description of the physical processes, including the dominating tidal forces that operate on Europa, and includes a comprehensive tour of Europa using images taken by Galileo's camera. The book reviews and evaluates the interpretative work carried out to date, providing a philosophical discussion of the scientific process of analyzing results and the pitfalls that accompany it. It also examines the astrobiological constraints on this possible biosphere, and implications for future research, exploration and planetary biological protection. Europa The Ocean Moon provides a unique understanding of the Galileo images of Europa, discusses the theory of tidal processes that govern its icy ridged and disrupted surface, and examines in detail the physical setting that might sustain extra-terrestrial life in Europa's ocean and icy crust. "

The work presented in this book is a major step towards understanding and eventually suppressing background in the direct search for dark matter particles scattering off germanium detectors. Although the flux of cosmic muons is reduced by many orders of magnitude in underground laboratories, the remaining energetic muons induce neutrons through various processes, neutrons that can potentially mimic a dark matter signal. This thesis describes the measurement of muon-induced neutrons over more than 3 years in the Modane underground laboratory. The data are complemented by a thorough modeling of the neutron signal using the GEANT4 simulation package, demonstrating the appropriateness of this tool to model these rare processes. As a result, a precise neutron production yield can be presented. Thus, future underground experiments will be able to reliably model the expected rate of muon-induced neutrons, making it possible to develop the necessary shielding concept to suppress this background component.

The aim of this book is to introduce scientific ballooning to the many people who are interested in the use of balloons for scientific applications. The book offers a basic understanding of the engineering details and the scientific research giving rise to balloon activities going on today. Above all, the book will serve as a guidebook for young scientists and researchers seeking to become involved in space science and technology by participating in balloon projects. The book deals with three types of balloons: large stratospheric balloons used for scientific purposes, rubber balloons used for aerological observations, and planetary balloons to be used in the atmospheres of other planets. The book provides many figures and photographs, and offers a systematic description of balloon technologies and related matters from historical background to current research topics. The contents include a theoretical discussion of ballon shape design, analysis and synthesis of flight dynamics, actual launching procedure, flight operations, and typical applications of ballooning in various scientific fields. Detailed meteorological descriptions, especially of the Earth's stratosphere and the atmosphere of other planets, are provided for investigating actual flight behavior.

Use of occultation methodology for observing the Earth's atmosphere and climate has become so broad as to comprise solar, lunar, stellar, navigation and satellite crosslink occultation methods. The atmospheric parameters obtained extend from the fundamental variables temperature, density, pressure, water vapor, and ozone via a multitude of trace gas species to particulate species such as aerosols and cloud liquid water. Ionospheric electron density is sensed as well. The methods all share the key properties of self-calibration, high accuracy and vertical resolution, global coverage, and (if using radio signals) all-weather capability. Occultation data are thus of high value in a wide range of fields including climate monitoring and research, atmospheric physics and chemistry, operational meteorology, and other fields such as space weather and planetary science. This wide area of variants and uses of the occultation method has led to a diversi fication of the occultation-related scientific community into a range of different sub-communities, however. The 1st International Workshop on Occultations for Probing Atmosphere and Cli mate-OPAC-1- held September 16-20, 2002, in Graz, Austria, has set in ex actly at this point. OPAC-1 aimed at providing a casual forum and stimulating at mosphere fertilizing scientific discourse, co-operation initiatives, and mutual learning and support amongst members of all the different sub-communities. The workshop was attended by about 80 participants from 17 different countries who actively contributed to a scientific programme of high quality and to an excellent workshop atmosphere, which was judged by the participants to have fully met the aims expressed.

A fundamental, profound review of the key issues relating to the early universe and the physical processes that occurred in it. The interplay between cosmic microwave background radiation, large scale structure, and the dark matter problem are stressed, with a central focus on the crucial issue of the phase transitions in the early universe and their observable consequences: baryon symmetry, baryogenesis and cosmological fluctuations. There is an interplay between cosmology, statistical physics and particle physics in studying these problems, both at the theoretical and the experimental / observational levels. Special contributions are devoted to primordial and astrophysical black holes and to high energy cosmic rays and neutrino astrophysics. There is also a special section devoted to the International Space Station and its scientific utilization.

Written by an international team of experts, this set of tutorial reviews provides a coherent and accessible summary of the current state of supernova research in all of its facets. The newly detected gamma-ray bursts are discussed in this context. While primarily addressing astrophysicists and astronomers, this book will also be of interest to cosmologists and nuclear physicists working on supernova-related issues.

Many books have been written about the Big Bang and how the universe became the way it is today. But what about the future of the universe? What will happen to the Earth and solar system? What about our galaxy? Indeed, how long will the universe as we recognize it survive? The Future of the Universe takes the reader on a journey through space and time, beginning with a long look at the Earth and solar system, voyaging to the outermost galaxies, and finishing with speculations about the life and fate of the entire universe.

This volume presents results from the ESO workshop Multiple Stars across the H-R Diagram, held in Garching in July 2005. It covers observations of multiple stars from ground and space, dynamical and stellar evolution in multiple systems, formation and early evolution of multiple stars, and special components of multiple stars. The book reviews the current state of observational and theoretical knowledge and discusses future studies for further progress in the field.

G. Beutler's Methods of Celestial Mechanics is a coherent textbook for students as well as an excellent reference for practitioners. The first volume gives a thorough treatment of celestial mechanics and presents all the necessary mathematical details that a professional would need. The reader will appreciate the well-written chapters on numerical solution techniques for ordinary differential equations, as well as that on orbit determination. In the second volume applications to the rotation of earth and moon, to artificial earth satellites and to the planetary system are presented. The author addresses all aspects that are of importance in high-tech applications, such as the detailed gravitational fields of all planets and the earth, the oblateness of the earth, the radiation pressure and the atmospheric drag. The concluding part of this monumental treatise explains and details state-of-the-art professional and thoroughly-tested software for celestial mechanics.

This volume is concerned essentially with the modern developments in reflecting telescope optics. In the last twenty years, modern technology has revolutionized not only manufacturing and test procedures but also the whole area of quality specification with the introduction of active control into the functioning telescope. Other subjects covered here are alignment of telescope optics, atmospheric optics, including adaptive optics, reflecting coatings and ancillary equipment (adapters and baffles). Although an independent work, Vol. II is heavily cross-referenced with Vol. I. It is richly illustrated and gives, together with Vol. I, the most complete list of references available; it can also therefore be regarded as a source book.

More than half of all stars in the universe formed and evolved as binary systems and their study is essential for understanding stellar and galactic evolution. The six lectures in this book give both a readable introduction and an up-to-date review of nearly all aspects of research into binary stars, including the range from common binaries to more exotic systems composed of white dwarfs, neutron stars and black holes.

This book explores cataclysmic variables with and without strong, overpowering magnetic fields. You ll read about stars with densities ranging from that of the Sun to the degenerate matter of white dwarfs to the ultra-compact states of neutron stars and black holes. One of the objects examined and discussed is the Double Pulsar, highlighting what observations have told us about fundamental physics.

The second Erice course in the school of Particle-Astrophysics was held in May, 1988. The topic choosen was Dark Matter. This is one of the most exciting top ics at the interface of particle physics and astrophysics. It is developing rapidly now due to a coming together not only of the theoretical concepts from the early universe with the theoretical concepts of galaxy formation, but also the coming to gether of the theorists, experimentalists and observers. It is with Dark Matter, the combined interrelated topics of galaxy formation and the generation of large scale structure that we see a confrontation of the exotic ideas from the early universe, such as phase transitions and unification, coming face to face with the realities of traditional observational cosmology. These realities have recently been heightened by the tremendous number of new observations, demonstrating that large scale structure of the universe is far more complex than anybody had suspected. In particular, we now see large scale foam, apparent large scale velocity fields, indicating devations from the Hubble flow, large scales of the order 100 Mpc, and galaxy formation occurring at high red shifts much greater than unity. We also see an apparent correlation of clusters of galaxies that may even exceed the c- relation of galaxies despite their being on much larger scales with lower average densities."

This book contains a series of lectures given at the NATO Advanced Study Institute (ASI) "Structure Formation in the Universe," held at the Isaac Newton Institute in Cambridge in August, 1999. The ASI was held at a critical juncture in the development of physical cosmology, when a flood of new data concerning the large scale structure of the Universe was just be coming available. There was an air of excitement and anticipation: would the standard theories fit the data, or would new ideas and models be re quired? Cosmology has long been a field of common interest between East and West, with many seminal contributions made by scientists working in the former Soviet Union and Eastern bloc. A major aim of the ASI was to bring together scientists from across the world to discuss exciting recent developments and strengthen links. However, a few months before the meeting it appeared that it might have to be cancelled. The war in the former Yugoslavia escalated and NATO began a protracted bombing cam paign against targets in Kosovo and Serbia. Many scientists felt uneasy about participating in a NATO-funded meeting in this situation. After a great deal of discussion, it was agreed that the developing East West conflict only heightened the need for further communication and that the school should go ahead as planned, but with a special session devoted to discussion of the legitimacy of NATO's actions."

In recent years there has been a steadily increasing cross-fertilization between cosmology and particle physics, on both the theoretical and experimental levels. Particle physics has provided new experimental data from the big accelerators in operation, and data from space satellites are accumulating rapidly. Cosmology is still one of the best laboratories for testing particle theory. The present work discusses such matters in the context of inflation, strings, dark matter, neutrinos and gravitational wave physics in the very early universe, field theory at the Planck scale, and high energy physics. A particular emphasis has been placed on a new topology for spatial infinity, on the relation between temperature and gravitational potential, a canonical formulation of general relativity, the neutrino mass, spin in the early universe, the measurement of gravity in the 10--100 m range, galaxy--galaxy and cluster--cluster correlation, black holes, string theory and string/string duality. The work also presents a beautiful review of high energy elementary particle physics, treating the meaning, status and perspectives of unification and standard model gauge couplings.

Solar Physics publishes up to two Topical Issues per year that focus on areas of especially vigorous and active research. The present Topical Issue contains papers of recent results on the solar corona, as well as on the transition region and low solar wind. The majority of these papers, which were all refereed in accordance with the standards of Solar Physics, were presented in August 1999 at a workshop held in Monterey, California. The authors were offered the opportunity to present relevant parts of their contributions on an accompanying CD ROM of this Topical Issue. The Sun's magnetic field is responsible for the spectacularly dynamic and intri cate phenomenon that we call the corona. The past decade has seen an enormous increase in our understanding of this part of the solar outer atmosphere, both as a result of observations and because of rapid advances in numerical studies. The Yohkoh satellite has observed the Sun now for over eight years, producing spectac ular sequences of images that convey the complexity of the corona. The imaging and spectroscopic instruments on SOHO have added information on the cooler part of the corona. And since April of 1998 TRACE has given us very high resolution images of the 1-2 MK corona, at cadences that allow detailed observations of field oscillations, loop evolution, mass ejecta, etc.

IAU Transactions are published as a volume corresponding to each General Assembly.

Volume A is produced prior to the Assembly and contains Reports on Astronomy, prepared by each Commission President. The intention is to summarize the astronomical results that have affected the work of the Commission since the production of the previous Reports up to a time which is about one year prior to the General Assembly.

Volume B is produced after the Assembly and contains accounts of Commission Meetings which were held, together with other material. The reports included in the present volume range from outline summaries to lengthy compilations and references.