This book presents an up-to-date detailed description and categorisation of the large range of astronomical objects that fall under the general heading of nebulae, and then instructs the reader in the best ways to successfully observe and record them. Nebulae and How to Observe Them is a comprehensive mine of information for all levels of amateur observers, from the beginner to the experienced.

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.

Planetary Nebulae and How to Observe Them is for amateur astronomers who want to go beyond the Messier objects, concentrating on one of the most beautiful classes of astronomical objects in the sky. Planetary nebulae are not visible to the naked eye, but they are a fascinating group of telescope objects. This guide enables a user equipped with an average-sized amateur telescope to get the best out of observing them. Topics covered include their astrophysical make-up, history of their discovery, classification and description, telescopes to use, filters, and observing techniques - in short everything anyone would need to know to successfully observe planetary nebulae. The book describes the various forms these astronomical objects can take and explains why they are favorite targets for amateur observers. Descriptions of over 100 nebulae personally observed by the author using telescopes of various sizes are included in the book. Readers can create their own observing program or follow the list of these captivating objects, many of which are found within our own Milky Way Galaxy.

No modern astronomer made a more profound contribution to our understanding of the cosmos than did Edwin Hubble, who first conclusively demonstrated that the universe is expanding. Basing his theory on the observation of the change in distanct galaxies, called red shift, Hubble showed that this is a Doppler effect, or alteration in the wavelength of light, resulting from the rapid motion of celestial objects away from Earth. In 1935, Hubble described his principal observations and conclusions in the Silliman lectures at Yale University. These lectures were published the following year as "The Realm of the Nebulae," which quickly became a classic work.

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.

This written account of the Symposium on Planetary Nebulae was prepared from manuscripts submitted by the participants. Nearly every paper that was presented at the meeting is reproduced here, in either complete or abbreviated form. The dis cussions have been somewhat shortened and rearranged, but we have tried to preserve the essential points and the general tenor of the exchanges. Participants who spoke in the discussion were asked immediately for written remarks, which were then edited, reproduced, and circulated at the meeting by the highly effective local Secretariat organized by Dr Perek. In addition, notes of the discussion taken by Mrs Edith F. Swan and by the undersigned were used. We wish to thank all the authors for their unusually good cooperation. We are especially grateful to Dr Minkowski, who kindly provided many excellent repro ductions of Mount Wilson and Palomar photographs, mostly taken by himself, of various planetary nebulae. We are particularly indebted to Mrs Swan, who attended the Symposium, made notes on the papers and discussions as they occurred, and did much of the checking and editing of the manuscripts. In addition, we are very grateful to Mrs Evelyn Seaver, who also did much of the checking, editing, and retyping of manuscripts, and to Dr B.L. Webster, Miss Rebecca Todd, Mr Joseph Tapscott, and Mr Dennis Schatz, who provided excellent assistance in the preparation of this volume.