Planetary nebulae represent the brief transition between Asymptotic Giant Branch stars and White Dwarfs. As multi-wavelength laboratories they have played a key role in developing our understanding of atomic, molecular, dust and plasma processes in astrophysical environments. The means by which their wonderfully diverse morphologies are obtained is currently the subject of intense research, including hydrodynamical shaping mechanisms and the role of binarity, stellar magnetic fields and rotation. Their contribution to the chemical enrichment of galaxies is another very active research area, as is the ever growing use of their narrow high luminosity emission lines to probe the dynamics and mass distributions of galaxies and the intergalactic media of clusters of galaxies. IAU S234 summarises the current status of research on the properties and processes of planetary nebulae, as reported in reviews and papers by leading experts working in the field.

Planetary nebulae play a key role in stellar evolution as an important fraction of stellar matter in the Universe goes though the asymptotic giant branch and planetary nebula phases in its lifetime. They are major contributors to the chemical enrichment of the galaxies, especially for nitrogen and carbon. They also act as multi-wavelength laboratories for understanding atomic, molecular, dust, and plasma processes in different astrophysical environments, and for studying the dynamics and mass distributions of galaxies. IAU Symposium 283 brought together experts from a variety of countries to present new results including: those from IPHAS and HERSCHEL; the detection of fullerenes in our galaxy and its neighbors; a new catalogue of about 600 planetary nebulae spectra; and the latest three-dimensional models of the common envelope phase. This volume is an essential reference for all those specializing in planetary nebulae.

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.

A complete record of the formal organisational and administrative proceedings of the XXVII General Assembly of the International Astronomical Union.

Planetary nebulae are a keystone for the understanding of the evolution of stars, for deep insights into the physical processes prevailing in highly excited dilute nebulae, and for the chemical evolution in galaxies. These objects, displaying an intriguing morphology, have a `short' lifetime of a few tens of thousands of years, and have become one of the best studied classes of celestial sources. However, despite large and successful efforts from both the observational and theoretical side, planetary nebulae still keep some of their secrets (like the widely unknown distances) and will undoubtedly also be objects of thorough investigations in the years to come.

"Planetary nebulae play a key role in stellar evolution as an important fraction of stellar matter in the Universe goes though the asymptotic giant branch and planetary nebula phases in its lifetime. They are major contributors to the chemical enrichment of galaxies, especially for nitrogen and carbon. They also act as multi-wavelength laboratories for understanding atomic, molecular, dust, and plasma processes in different astrophysical environments, and for studying the dynamics and mass distributions of galaxies. IAU Symposium 283 brought together experts from a variety of countries to present new results including: those from IPHAS and HERSCHEL; the detection of fullerenes in our galaxy and its neighbors; a new catalogue of about 600 planetary nebulae spectra; and the latest three-dimensional models of the common envelope phase. This volume is an essential reference for all those specializing in planetary nebulae research."--Page 4 of cover.

Every 5 years since 1967 a meeting has been held to discuss the subject of planetary nebulae and their central stars. Previous meetings have been held in Tatranska Lomnica (Czechoslovakia); Liege (Belgium); Ithaca, New York (U. S. A); and London (Great Britain). IAU Symposium 131 was sponsored by IAU Commision 34, on Interstellar Matter and co-sponsored by IAU Commisions 35 and 36 on Stellar Constitution and Theory of Stellar Atmospheres. The symposium was held at the Universidad Nacional Autonoma de Mexico in Mexico City, October 5-9, 1987. It took place in one of the old buildings of the University of Mexico in the downtown area. The inner patio of the building provided very pleasant surroundings for the poster sessions and for extensive discussions among the participants. The meeting was attended by 160 scientists from 22 countries. The Scientific Organizing Committee,under the chairmanship of J.B. Kaler, prepared a comprehensive scientific program based on a set of invited presentations. All contributed papers were presented in poster form. The Scientific Organizing Committee would like to thank the staff of the University of Illinois Department of Astronomy: Dr. Ron Allen for granting financial support; Carol Stickrod, Louise Browning, Deana Griffin and Sandie Osterbur for their help with the organization. IAU provided economic assistance to a group of young astronomers.