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.
An even greater number of planetary nebula can be found within the NGC and IC catalogs and are available elsewhere on this site (see here). As is evident from the images below, planetary nebulae are beautiful 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).
Note: Abell 43 is a small and dim planetary nebula in Ophiuchus. Although it is generally spherical, close inspection of the image below will reveal a small distortion on the southeastern wall. What is of greater interest is the intricate filamentary structure which appears as a lace network around the spherical body of the nebula, really brought out exquisitely by longer focal length instruments (see Friederich et al here), and which has been likened to an eikosahedron and similar to the structure of a soccer ball; hence, for its nickname ("Galactic Soccerball"). The central star in Abell 43, WD 1751+106, is quite unique due to the fact it is one of only four known examples of a hydrid PG1159 white dwarf star where hydrogen deficiency is not observed (see Solheim et al here). Furthermore, the central star is a pulsating variable with six different pulsation modalities and which may be attributable to partially ionized carbon in its atmosphere (Solheim et al from above). Abell 43 has been estimated by Kaler et al to lie at a distance of 6,850 light-years away and to span another 1.34 light-years across.
Please click on the image below to display in higher resolution (1200 x 950)
RA / Dec:
17h 53' 32.3" /
+10° 37' 19.6"
80" x 74"
July 04-05, 2011
22:45 - 02:50 UT+3
AP 305/f3.8 Riccardi-Honders
AP 1200GTO GEM
Baader LRGB CCD filters
1.36" per pixel