A large number of planetary nebulae can be found within the NGC and IC catalogs and are available elsewhere on this site (see here). As illustrated by the image below, planetary nebulae are beautiful objects to look at thanks to the glowing and colourful gaseous shrouds which make their planetary appearance and colouration possible as a result of stars having exhausted their nuclear material and having reached the last stages of their life. Some of the more exotic planetary nebulae include the Cat's Eye (NGC 6543), the Saturn Nebula (NGC 7009), the Ghost of Jupiter (NGC 3242) and the Owl Nebula (M97).

George Abell's examination of the Palomar Observatory Sky Survey in the mid 1960's yielded 86 planetary nebulae which have proven to be an observer's dream challenge, for many of these celestial objects are not only very faint in magnitude even under very dark skies but are also relatively large with dimensions often measured in minutes in lieu of seconds. Later analysis of Abell's catalog revealed that at least four of these objects, namely Abell 11, 32, 76 and 85, are not planetary nebulae at all. For the avid observer, an O-III filter is highly recommended in order to have any hope of visually detecting these elusive wonders. Abell's planetary nebulae have been classified under a web page of their own on this site (see here).

Note: A very interesting planetary nebula is Campbell's Hydrogen Star in Cygnus and which lies within 2.5 degrees of Albireo. This planetary nebula is quite small and with an apparent diameter of only five arc-seconds, thus easily appearing star-like when viewed through an eyepiece. What makes this particular planetary nebula interesting is the fact that its central star (mag 11.3) has reached the end of its life and has started to shed material into space, thus making it also a Wolf-Rayet nebula. Parallax measurements from the early 1900's suggest Campbells's Hydrogen star to lie at a distance of 1,125 light-years away.