Our lives here on our small world are intimately tied to the lives of the stars. The matter that we are made of was mostly made either in the cores of stars or in the explosion of stars. In both cases we owe our existence to the deaths of a untold numbers of stars billions of years in the past. Our own star， the Sun， will also succumb to the march of time. Having spent its nuclear fuel it will also send the elements it made during its lifetime into the Galaxy. It is possible that in the Sun's death throes it will become a planetary nebula.
　　Planetary nebulae mark the deaths of low and intermediate mass stars. Though not as instantaneously spectacular as the supernova deaths of high mass stars， planetary nebulae have a beauty all their own. Though we have observed them for a few hundred years， it is only in the past few decades that we have figured out what they are and their place in the lives of stars. Even now there are many aspects of planetary nebulae that elude our understanding making these objects the subject of active research.
　　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.