The purpose of this book is to give a detailed description of the planetary nebulae including the relevant astronomical observations and their interpretation. Considerable attention is given to the evolution of these objects as well as to their physical characteristics. I t is hoped that the book be useful to both advanced research workers and to students with some background in astronomy. In this regard, the book should serve as a text as well as a reference work. The many tables included are expected to be useful for both purposes. The references are generally not included in the text except for historical purposes in an effort to improve readability. References are given at the end of each chapter together with sufficient text to describe their content. No attempt has been made to make the list of references complete; on the contrary it has generally been limited to the most recent literature on the subject which in turn refers to earlier research. Again, exceptions have been made for references of historical interest.

Planetary nebulae, glowing shells of ionized gas, are the spectacular products of the evolution of low- and intermediate-mass stars. For astrophysicists, they are important laboratories for the understanding of atomic, molecular, dust, and plasma processes in different cosmic environments; they enable the exploration of the fundamental physics of single and binary star evolution including nucleosynthesis, rotation, mass transfer and loss, and magnetic fields; and they help trace stellar populations, the kinematics, and chemistry of galaxies including our own galaxy, the Milky Way. This volume reviews the current status of this vibrant research field in the form of invited reviews, contributed talks, and posters presented at the IAU Symposium 323. It should be of interest to researchers and advanced students interested in this field and in related fields, including stellar physics, the interstellar medium, and Galactic and extragalactic astronomy.

While there have been many books on cosmology and galactic and stellar evolution in which abundance analysis of astrophysical objects has played some part, this book is the first one for several years where specialists in the various relevant fields discuss the basis and implications of the subject as a whole. The major aim of the book is to bring together the results from high redshift studies and galactic studies in a coherent way and to cover relevant aspects of nuclear and atomic physics.

IAU Symposium 268 presents an overview of the most recent observational and theoretical research on the formation and evolution of light elements in the Universe: H, He, Li, Be, B, and their isotopes. Astrophysicists from a variety of subfields discuss recent developments that will improve our understanding of the light elements and provide important clues to stellar and galactic evolution, Big Bang nucleosynthesis, and cosmology. Striking observational progress has been achieved recently through the advent of next generation ground- and space-based telescopes, such as the cosmic microwave background experiments that allow the accurate determination of the baryon density of the Universe. New theoretical breakthroughs in describing stellar interiors and the chemical evolution of complex systems and the remaining challenges in this field are also addressed. This critical review is a useful resource for all those interested in the chemical evolution of the Universe.

In this book we will look at what planetary nebulae are, where they come from and where they go. We will discuss what mechanisms cause these beautiful markers of stellar demise as well as what causes them to form their variety of shapes. How we measure various aspects of planetary nebulae such as what they are made of will also be explored. Though we will give some aspects of planetary nebulae mathematical treatment, the main points should be accessible to people with only a limited background in mathematics. A short glossary of some of the more arcane astronomical terms is at the end of the book to help in understanding. Included at the end of each chapter is an extensive bibliography to the peer reviewed research on these objects and I would encourage the reader interested in an even deeper understanding to read these articles.

Astronomy and Astrophysics Abstracts, which has appeared in semi-annual volumes since 1969, is de voted to the recording, summarizing and indexing of astronomical publications throughout the world. It is prepared under the auspices of the International Astronomical Union (according to a resolution adopted at the 14th General Assembly in 1970). Astronomy and Astrophysics Abstracts aims to present a comprehensive documentation of literature in all fields of astronomy and astrophysics. Every effort will be made to ensure that the average time interval between the date of receipt of the original literature and publication of the abstracts will not exceed eight months. This time interval is near to that achieved by monthly abstracting journals, com pared to which our system of accumulating abstracts for about six months offers the advantage of greater convenience for the user. Volume 13 contains literature published in 1975 and received before August 15, 1975; some older literature which was received late and which is not recorded in earlier volumes is also included. We acknowledge with thanks contributions to this volume by Dr. J. Bouska, who surveyed journals and publications in the Czech language and supplied us with abstracts in English, and by the Common wealth Scientific and Industrial Research Organization (C.S.I.R.O.), Sydney, for providing titles and abstracts of papers on radio astronomy. We want to acknowledge valuable contributions to this vol ume by Zentralstelle ftir Atomkemenergie-Dokumentation, Leopoldshafen, which supported our ab stracting service by sending us retrospective literature searches.

The Sun is merely one of some 200 billion stars that make up the Milky Way--and the Milky Way is only one of a billion galaxies in the known universe. Packed with fascinating facts and stunning photography, this book examines the Galaxy humans call home and travels light years away, to the domain of phenomena such as the Oort cloud.