The IAU Centenary Symposium was held at its General Assembly in Vienna in 2018. It starts with plenary lectures, by Malcolm Longair on 100 years of astronomy, astrophysics and cosmology, and by Catherine Cesarsky, who reflects on a century of IAU history. There follows reminiscences from past IAU presidents and general secretaries and presentations on various aspects of IAU history, including some of the famous astronomers who served the Union. The volume then examines the relations between the IAU and different geographical regions, including the issues relating to the Central Powers after World War I, and the "China crisis", when China withdrew from the Union in 1960 and was absent for two decades. The IAU's internal structures and organization are reviewed, along with trends in astronomical publishing and astronomical education. IAU S349 finishes with a vision of the IAU's future from its current president, Ewine van Dishoeck.

The International Astronomical Union (IAU) was founded in 1919, in the wake of the First World War, together with its sister Unions in related natural sciences. It will thus turn 100 years in 2019. Written by a mixed team of insiders and outsiders, this book presents the IAU in the changing context of the historical, scientific and technological development of astronomy during the past 100 years. While much important scientific progress took place already before 1945, the book naturally focuses on the accelerating evolution during the second half of the century. In the past few decades, the previously narrow IAU focus on organising professional astronomy has broadened to include societally relevant activities such as addressing the hazard of asteroid impacts, the planetary status of Pluto in the Solar System, and the hugely successful International Year of Astronomy. Most recently, it is spearheading a combination of science literacy and public outreach. The book will be of interest to professional astronomers as well as an astronomically interested general audience. The book features live personal interviews with as many of the key actors as still possible.

Relativistic Astrophysics brings together important astronomical discoveries and the significant achievements, as well as the difficulties in the field of relativistic astrophysics. This book is divided into 10 chapters that tackle some aspects of the field, including the gravitational field, stellar equilibrium, black holes, and cosmology. The opening chapters introduce the theories to delineate gravitational field and the elements of relativistic thermodynamics and hydrodynamics. The succeeding chapters deal with the gravitational fields in matter; stellar equilibrium and general relativity stability; and the properties of pulsar, rotating and neutron stars. The discussion then shifts to the association between gravitational collapse and black holes, as well as the astrophysical investigations of neutron stars and black holes. The final chapters examine the principles of gravitational waves and advances in understanding the field of cosmology. This book will be of great value to astrophysicists and related scientists.

This History has its origin in a suggestion, made in September 1990 by former IAU General Secretary Derek McNally, who felt "that a 75 year history of the Union was needed before the col lective memory of those who knew the Union before the Second World War vanished. It would then be a preparatory volume to a centennial history in 2019. " Indeed, of those who knew the Union that long ago, few are still with us. Six years ago, at Baltimore on August 2, 1988, listening and reminiscing at the Inaugural Ceremonies of the Union's 20th General Assembly, I realized that it was almost exactly half a century ago that, at the age of 24, I attended the Inaugurations at my "first" Assembly: on August 3, 1938 in Stockholm. Now, in 1994, this is almost 56 years ago, three quarters of the Union's age. Only vague recollections - no better than that -lead me back to this event, just before World War II. And so, this is not a history based on recollection, far from it. Recollection was helpful in that it allowed me, better perhaps than a younger author, to appreciate circumstances under which the letters and reports which form the basis for this History were written. The account is largely based on archival documents, collected from a wide variety of sources.

The Ever-Changing Sky provides a comprehensive and non-mathematical guide to spherical astronomy. The reader is guided through terrestrial and celestial co-ordinate systems, time measurement and celestial navigation, to the prediction of the rising and setting of the stars, Sun and Moon. It focuses on the geometrical aspects of the night sky without using complex trigonometry. The book progresses to a general study of the Earth and sky, including the stars and constellations (with useful star maps provided), the motions and appearance of the Moon, tides and eclipses, the orbits of the planets and the smaller bodies of the Solar System (asteroids, meteors, meteorites and comets). Finally, there is a brief overview of atmospheric phenomena (including rainbows and haloes). This text will be invaluable to students taking courses in naked-eye astronomy, amateur and professional astronomers, as well as more general readers wanting to know how the night sky changes.

IAU Symposium 278, the ninth of the 'Oxford' conferences on cultural astronomy, presents a diverse range of disciplinary perspectives on a set of problems that continue to raise exciting and challenging new research questions and promote vigorous debate. It extends discussions about cultural astronomy beyond the community of 'Western' academics to focus on the ethnoastronomy and archaeoastronomy of South America, Central and North America, and elsewhere. Highlights include vigourous debates about Chankillo, a recently discovered solar observation site in coastal Peru dating to c. 300 BC. The first IAU Symposium devoted to this topic not only discusses new discoveries and interpretations but also considers broader issues of mutual interest across disciplines in cultural astronomy, such as field methodology and social theory. This volume is valuable not just to researchers working in these fields, but to anyone who takes an interest in the protection of astronomical heritage.

Addresses astronomy education and research in developing countries, for astronomers promoting and supporting astronomy around the world.