Monday, November 03, 2008

Planetary Nebulae Visible in the Polluted Skies over Austink

As a hard working average amateur astronomer I have been working hard at espying planetary nebulae. Planetary nebulae may be stars that give off, or gave off a cloud of gas. The cloud of gas surrounding these stars is often visible even in light polluted skies. Therefore, an average amateur astronomer, like me, may be interested in espying them.

Yes. Keeping in touch with nature may be hard work for those average amateur astronomers trapped in an urban environment. Nevertheless, many of the planetary nebulae are sufficiently bright, glowing in the murk of the gray or grey sky, to find themselves espied by an average amateur astronomer.

Here is a list of planetary nebulae (pn) I have espied lately, that is, from the commencement of Beelzebubberiffic into the blessed mercy of Olwen White Track, the season, DY 2. Most observations were accomplished with a 10" F5 Newtonian reflector. However, many were made, or also made, with a 133.5mm Lomo Maksutov. Alas, I can not remember which were made with the Lomo. Certain, of them, though, like the Helix Nebula, might be impossible with the Lomo from this location.

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PN NGC #, Messier # if any, common name if any, constellation, commentary if any.

NGC 40, Cepheus
NGC 246, Cetus* I can’t actually see this one. But it is included here because I have tried really hard to see it, repeatedly.
NGC 650, M 76, Little Dumbbell, Perseus!
NGC 1501, Camelopardalis There are a great many interesting heavenly bodies nearby.
NGC 1535, Eriadnus
NGC 2392, Eskimo Nebula, Gemini!
NGC 2438, in the field of M 46, Puppis!!
NGC 3242, Ghost of Jupiter, Hydra!
NGC 3587, Owl Nebula, Ursa Major, requires filter
NGC 6210, Hercules
NGC 6309 Box Nebula, Ophiuchus, Ultrablock helps a lot,
NGC 6543, Cat’s Eye, Draco!
NGC 6572, Ophiuchus
NGC 6720, M57, Ring Nebula, Lyra!
NGC 6803, Aquila, filter helps a lot.
NGC 6804, Aquila, filter pretty much required.
NGC 6818, Little Gem, Sagittarius
NGC 6826, Blinking Planetary, Cygnus!
NGC 6853, M 27, Dumbbell, Vulpecula!
NGC 7009, Saturn Nebula, Aquarius!
NGC 7027, Cygnus, OIII and Ultrablock help this little blinker
NGC 7293, Helical or Helix Nebula, Aquarius, requires filter
NGC 7662, Blue Snowball, Andromeda!

Of these, the hardest ones to see/find, besides NGC 246 in Cetus, are NGC 3587, the Owl Nebula and NGC 7293, the Helix. Both these are only really visible from my location via filters, preferably the O-III.

An exclamation mark, ! indicates whether the pn is worth looking for/at twice, from this location, given all the light pollution.
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Mercy! I am a star hopper. Not because of any Luddite principles regarding new technology, but because I am cheap. The star hopper must find heavenly bodies manually, assisted only by visual aids including spectacles, binoculars, pointers, finders. Also, alas, to espy pn, multiple eps plus filters may be required.

Yes. Sometimes the aggravating pn is indistinguishable from other heavenly bodies, typically, the many tiny stars in the field of view (fov) of my trusty yet goofy 40mm plossl. So then I need to use a filter or a higher magnification ep. In this situation, I generally go to a 30mm ep or even a 20mm ep and maybe a filter before I can scan around and eventually espy the pn. Rarely, I have gone down as low as a 9mm ep for scanning purposes, but scanning with a 9mm ep is a serious drag due to light loss and the narrow fov. Plus, scanning with a 9mm ep is really hard work. Plus, I have never actually found a pn following this procedure. No. I eventually get too aggravated and give up.

My 30mm ep of choice for scanning at a higher magnification than the 40mm affords has been a 30mm Ultima. However, my Ultrablock filter and the threads of the Ultima are borderline incompatible. Doubtless, the filter threads on the Ultima are why it wound up for sale on Astromart. (I have about decided that purchasing used on Astromart is too cheap). My scanning ep of choice at 20mm is a Televue (TV) plossl, also acquired used on Astromart. My TV plossl is the kind with the annoying ring on the barrel that likes to catch in the 2" to 1.25" focuser adapter upon both insertion and extraction. Aggravating!

Given all this, I wish I had a 40-20mm parfocal zoom ep. I also wish for nocturnal power failures.

Another option for the hard work of scanning for pn involves 25 and 12.5mm University orthos. I have eschewed this option due to the relatively narrower FOVs these eps afford. But tonight, Goddess willing, I may try them out on NGC 1514 in Taurus.

Yes. NGC 1514 is my next pn to do. After that, I have a bunch more to do. I have a list.

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