THE SEASONAL BEST PLANETARY NEBULAE

Ah, springtime, when a young man's (or young lady's) fancy turns to ......  galaxies!  For northern hemisphere planetary nebula observers, there is indeed a sparsity of these glowing gems of the skies.  But only in number, and not necessarily in quality.  Southern hemisphere observers do have the edge this season, as many of the NGC and IC objects catalogued as planetaries lie well below 40 degrees southern declination.  The twenty-five pn's shown in the below table were selected to favor both hemispheres, and for those in the north, when their list is exhausted, pack up the telescope gear and head south!

Of the 600 planetaries in my current database, there are only 48 that lie between the Right Ascension of 09 hours and 14hours  59 minutes, which I arbitrarily picked as the 'spring' season. Of those 48, only 12 are at or are north of - 40 degrees declination, and only 4 are above the Celestial Equator!  In the table are 11 of those 12 'northern' pn's and 14 'deep south' pn's which offer a wonderful variety of structure, color, and form.

Among the quality objects viewable from the northern hemisphere are NGC 3242, known as the "Ghost of Jupiter", and NGC 3587, the "Owl Nebula", also well known as 'M97' in Messier's list. Another item of interest that is bordering my north-south line is NGC 3132, the "Eight-Burst Nebula", named after it's complex appearance in photographs.  Be sure to check them out, as well as the others, for each is different in it's own astronomical way.

In a departure from the format of the winter list, I am first listing the 'northern' objects in ascending Right Ascension (J2000.0), and then the list of the 'southern' objects.  Each list offers a tremendous range of size, magnitude, surface brightness, and difficulty.  I would be
most delighted to receive observing reports based on these objects, and of course, the reports themselves would be posted here on the website if you have no objection.
 PLANETARIES WITH OBSERVABLE CENTRAL STARS

NGC 3132: spectral type A2V+sdO; therefore this is not the star that luminesces the nebula.
NGC 3242: difficult due to the surface brightness of the nebula.
IC 3568:      spectral type O5f; most northerly known planetary nebula ( is it? Prove me wrong.)
 
PN’s visible from cities or moderate light polluted areas:

NGC 3132
NGC 3242
NGC 3587
NGC 4361

Many of the southern pn's listed in the table.

As always, the use of a nebula filter will most likely enhance the observability of these planetaries.  The filters recommended are OIII, UHC, and Deepsky in that order.
http://www.blackskies.org    snyder@ix.netcom.com    11/16/97