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: The image below, commonly referred to as the Little Dumbbell Nebula due its striking resemblance to the larger Dumbbell Nebula in Vulpecula, is the 76th entry in Charles Messier's famous catalog of deep sky objects and which was originally discovered by Pierre Mechain in 1780. It represents one of only four planetary nebulae observed and catalogued by Messier along with the Ring Nebula (M57) in Lyra and the Owl Nebula (M97) in Ursa Major. The Little Dumbbell with a magnitude of 10.1 is one of the dimmest entries within the Messier catalog; it lies in the eastern portion of Perseus; and was only confirmed to be a planetary nebula in 1918 by Heber Doust Curtis. Although the brighter portion of the nebula just exceeds one-arc minute in apparent diameter, more detailed analyses have revealed a dim shroud reaching out nearly five arc-minutes in diameter and which is believed to span up to 21 light-years across. Estimates as to the distance of M76 vary rather widely and range from 1,700 to 15,000 light-years away with 3,400 light-years being a commonly cited figure.

As with all planetary nebulas, a "central" star is responsible for the impressive and colourful shrouds of gases, for it represents the source of the massive stellar explosion. In this particular instance involving M76, the 16.6 magnitude star at the center of the shroud (especially visible in the higher analysis image available by clicking on the image below) is the source of the gaseous envelopes that surround it.