PK 217+14.1 aka Abell 24 is a rather large planetary nebula in Canis Minor. Distances to planetary nebulae are hard to determine. This one is close enough a ballpark answer can be obtained by parallax though working at the extreme limits of this mode. The best value I could come up with is 1700 light-years with an error bar going from 1525 to 2063 light-years. A surprisingly small range for this distance. At least to me. The paper is at:
http://iopscience.iop.org/article/10.1086/510348/pdf;jsessionid=73E25EF08CA5CB9C039A2584E798C213.c3.iopscience.cld.iop.org
Assuming the 1700 light-year distance the nebula is about 3.3 light years across assuming it is 400 seconds of arc across. All sources say it is only 285" but measuring my FITS images I get 400 seconds. The 285 is from measuring only the brighter portions it appears. The full image is at 1.01 seconds per pixel so you can measure it yourself with any decent image program. The central star is very obvious as the blue star at its very center. It is providing the energy to illuminate the nebula. It may be a dead star (no longer creating energy by fusion) and a very small white dwarf (well blue dwarf) but it is pouring out the ultra-violet light that causes the hydrogen and nitrogen in the nebula to glow bright red. Red planetaries like this are rather uncommon. Most shine with a teal color of glowing oxygen III ions.
While a few dozen galaxies are scattered about the field, none have any redshift data. Though one just off the frame is sending its glow into the very bottom of my image below the nebula. It is CGCG 002-018. A rather large elliptical galaxy some 260 million light years away. I didn't realize it was there or I'd have planned to include it.
14" LX200R @ f/10, L=6x10' RGB=2x10'x3 (no H alpha), STL-11000XM, Paramount ME | 
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| Planetary Nebula Abell 39 is a rather large bubble in western Hercules. It is one of the most symmetrical planetary bubbles known. I found several papers defining its distance but they are in wide disagreement.
1700 light-years: http://mnras.oxfordjournals.org/content/357/2/619
6000 light-years: http://mnras.oxfordjournals.org/content/353/2/589
6850 light-years: http://iopscience.iop.org/0004-637X/560/1/272/
Wikipedia says 6800, APOD says 7000. I suppose it is safe to say the 1700 figure is likely very wrong. Using 6800 light-years I get a size of 5.6 light-years which seems large to me for such a bright planetary. Usually, they are very faint at this size.
The central star is quite bright and not in the center but about 2" off center. Usually, this means the motion of the nebula through the interstellar medium has caused the nebula to lag behind the central star. The brightest edge usually denotes a planetary's leading edge. If so then the star is displaced toward the trailing edge, not the leading edge. It appears that in this case the off-centered star may be due to velocity differences at the nebula's creation and the nebula is not showing motion through the interstellar medium at all. This is an oddity that needs more study.
Being in a part of the sky with little dust and gas a lot of background galaxies are visible in the image. I've annotated all with redshift values at NED. A surprising number have a distance of about 1.69 billion light-years, including the three seen through the nebula itself. Yet I found no listing for a galaxy group at that distance in my image or within 40 minutes of its center. One of the three in the nebula is a ULIRG which stands for Ultra Luminous Infra Red Galaxy. It's IR status was discovered by IRAS, the first space telescope that cataloged IR sources in the sky.
14" LX200R @ f/10, L=4x10' RGB=2x10' STL-11000XM, Paramount ME | 
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| Abell 48/Pk 29+0.1 is a very red planetary nebula in eastern Aquila just above Scutum, right in the heart of the Milky Way. One estimate of its distance put it at 6,200 light years. That would make it about 1.3 light-years in diameter if my measurement of 43" for a diameter is correct. There are three rather red stars across the nebula, the middle one, even though not at all blue, is considered to be the central star. The nebula is considered to be dimmed by over 2 magnitudes due to dust in our galaxy. This likely reddens the star but I doubt it accounts fully for its red color. It is a very rare type for a planetary nebula being a WN class Wolf-Rayet star (this classification is not fully accepted from what I see). The N indicates its atmosphere is dominated by nitrogen. Only one planetary nebula is known for certain to have such a central star, IC 4663. At -45 degrees I won't be imaging it! Abell 48 is very red and in the form of a double ring. This has caused some to consider it a nebula around a massive star rather than a planetary nebula though most favor the planetary nebula classification. There's some indication this is a runaway system. A good paper on this object that's not as hard to read as many is at http://arxiv.org/pdf/1301.1944v2.pdf
Another paper also finds the star is WN but says it is a low mass star, not high mass and puts its distance at 5,200 light-years which gives a diameter of 1.1 light-years. http://arxiv.org/pdf/1301.3994v1.pdf
For yet another take on this by some of the same authors of the second link above see: http://arxiv.org/pdf/1212.5382v1.pdf
All of the papers are very recent with the oldest (last listed) dating to December 21, 2012. Thus none existed when I put it on my to-do list nor when I took the data in August of 2012.
14" LX200R @ f/10, L=4x10' RGB=2x10' STL-11000XM, Paramount ME | 
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| Abell 53/PK 40-0.1 is a one-half minute in diameter nice red ring planetary nebula in Aquila. I found several papers giving distances to this nebula. Some were behind paywalls, including the newest. So I'm stuck with older papers about 10 years old saying a distance of about 5500 light-years with a rather large range. Using the 5500 figure it would be about 0.8 light-years across. The central star is only about magnitude 20.8 or 20.9 depending on the source. Other than this I'm not able to find much on this nebula or the field for that matter. It is in the dark rift that passes through Aquila so everything is obscured that lies beyond the dust.
14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME | 
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| Abell 61 is a planetary in Cygnus near the northeast border with Lyra. It is about the size of the M97, the Owl Nebula, but much fainter. So faint nearly all the online images of it are narrow band. Being a contrarian I gave it a go with LRGB only and found it much easier than I expected if the weather hadn't have been a problem. Took me 3 nights to get what little data I did. Even then I screwed up and took some color data binned 3x3 and some binned 2x2. Of 19 color frames, only 5 were usable due to clouds. I got only 4 luminance frames and one of those was not very good but did help improve the signal to noise ratio but reduced resolution. I used it anyway. Color frames were one each at 3x3 binning and one of blue and green at 2x2. That's all I got that was usable. I need to revisit it as I think I can get far more detail with more frames. Still, considering conditions, this isn't as difficult an object as its reputation would indicate.
It's central star NSV 11917 is a variable star. Distances to planetary nebulae are usually very hard to pin down unless close enough for parallax measurements. I found two for this one. One said 850 parsecs (2800 light-years). Another, using a different method that tends to give a distance greater than parallax says 1400 +800 -500 parsecs (4600 +2600 -1600 light years). The 850 parsec estimate would fit within the error bar of the latter near the bottom end which is where parallax measurements fell so until something better comes along I'll go with the 850 parsec estimate. It is about 200" of arc across in my image. At that distance, it would be 0.8 parsecs in diameter (2.6 light-years). That seems reasonable as well.
http://adsabs.harvard.edu/cgi-bin/nph-bib_query?2001A%26A...367..973N&db_key=AST
Another paper indicates the planetary is interacting with the interstellar medium. This may explain why the northwest side is sharp and bright while the southwest side is weak and indistinct. The paper indicates they believe the interaction is just beginning.
http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1994AJ....108..188T&db_key=AST
Several narrow band images show what the imager says is a strong H alpha signal but the above paper says this is NII rather than H alpha. So if imaging this one don't use a 3nm H alpha filter.
I couldn't find anything on the variability of the central star.
There are several galaxies in the image, one seen right through the planetary to the left of the central star. Unfortunately, most aren't listed in NED, including the one by the central star. Those that are listed are all in the 2MASS survey and thus strong in IR frequencies. None have even a magnitude listed let alone redshift data. The white galaxy below Abell 61 is 2MASX J19191643+4610542. Below it and to the right a bit is the very red spiral 2MASX J19191404+4608332/PGC 2276111. Down and left of it is a faint blue galaxy not in NED. Down and further left is a pair of blue galaxies. One an obvious blue galaxy, likely a spiral with a compact blue galaxy companion to its lower right. Neither of these are in NED. Directly left (east) of Abell 61 just before you get to a very bright blue star is 2MASX J19202393+4614166 hiding behind a field star. It is also known as PGC 2277772. There are several other red smudges listed at NED but nothing with any interesting information so I'll stop here.
14" LX200R @ f/10, L=4x10' R=1x10'x3 GB=1x10'x3 and 1x10'x2, STL-11000XM, Paramount ME | 
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| The planetary nebula Abell 69 is a very faint planetary in Cygnus about 60% of the way from NGC 6888 (the Crescent Nebula) and M29 so embedded in weak background H alpha emission that fills this area. Add to that this was taken two nights that everything went wrong. I'm often asked if that happens and I have to say it is very rare except for clouds moving in on me of course. But as to goofs on my part, those rarely happen and never two nights in a row but boy did they for this one.
I had done some work on the scope and somehow the dew shield was removed but not reinstalled. Add to that that somehow the dew heater had been plugged into the side of the controller that was turned off. The controller can control two separate heaters but I only have one so the other side is off. Thus I had no heat and no shield. This was the night I took the LRGB data. I thought it weak. Next day I went out to the observatory and found the dew shield hadn't been put on. Aha, that allowed dew (I am running 20C above normal this winter) to form on the corrector. Even with heat I need the shield as well unless I turn on the heater so high it distorts the corrector. I reinstalled the heater and decided the RGB data would color the stars but I'd have to use H alpha for the stars or retake the L channel. With weather issues the next clear night I took the H alpha. That too was weaker than it should have been. I saw that as the third frame came in. I went out to find the dew heater cold. Took me a bit to realize it was plugged into the wrong side of the controller. The corrector was frosty. I cleared it with a hair dryer but by then the planetary was way too low and it has been cloudy ever since or too far west when the weather did clear some nights. I never got more H alpha nor luminance I'd wanted. It's now too far west for this year. I processed what I got. To add to the problems I somehow took the H alpha data using different center pointing coordinates. So I had to heavily crop the image. I guess I saved up all my goofs for this one object! Well not exactly. I tried for others with the dew shield and heater off that are so bad they will have to wait for next year. This was just the one that is sort of salvageable.
I find very little on this planetary. Visual observers, even in larger Dobs say it is very difficult and seen only fleetingly with averted vision. Even in a 30" it was seen only 50% of the time http://www.cloudynights.com/topic/79580-cn-report-filter-performance-comparisons/#entry1047500 . The description misses that it is a ring and elongated. A 25" failed totally at NSP http://www.cloudynights.com/topic/13464-finally-nsp-11-report-part-1/ . I found virtually no amateur images of this one for some reason. Most were wide field shots of NGC 6888 that picked it up as a tiny object near the edge of the field in narrowband images. Compared to those it came out far better than it deserved to.
I don't know if the apparent halo around the rectangular ring is part of the planetary or just a brighter area of the H alpha background -- or is it foreground? Anyone know?
14" LX200R @ f/10 and frosty corrector, Ha=3x30' RGB=2x10', STL-11000XM, Paramount ME | 
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| ABELL 70/PK 38-25.1/PN G038.1-25.4 is a planetary nebula in southeastern Aquila. The distance to it is rather vague. One paper (URL below) cites two values, 2500 and 5000 parsecs and rejects the closer as creating too many problems with their analysis of the nebula. For the parsec impaired that would be about 16,000 light years.
Visually it is quite interesting with a galaxy as a hat. Most say it resembles a diamond ring. Most images of this one show the center dark but I show blue nearly to the core. Might be how their images were stretched. In any case, it is not often you see two unrelated deep sky objects on top of each other like this. The galaxy is LEDA 187663 with a redshift light travel time distance of 253 million light-years. That puts it nearly 16,000 times further than the planetary that is possibly 16,000 light-years away. A numerical oddity!
The central star of the nebula is a double star. And a rare type of binary known as a barium star. They seem to only exist in planetary nebula and only a very few of those. Another reason this is an atypical planetary nebula. You can read all about this at http://arxiv.org/pdf/1109.1519v1.pdf .
This one is low in my sky where I need exceptional seeing which didn't happen the night I took this. Another problem is that it lies right on the geostationary satellite belt as seen from my latitude. The result was a zillion satellite trails through the image, most just above the nebula though two normal satellites flew through the field as well. OK, not a zillion, just 37 in 100 minutes time. I think that's a record for me but I haven't been keeping track. There were two asteroids as well but they were lost in processing out the satellites. Also, the sky was unusually bright this night which prevented me from going very deep. This is why I chose this relatively bright object as one that could cut though my strong airglow. It also was a very humid night further reducing transparency according to my notes. Another I need to revisit under better conditions. I probably should have picked on some star cluster instead. I didn't know how bad it was until I processed the data. But I dread the thought of processing out all those satellite trails. Due to it being low I have to take it half on one side and half on the other side of the meridian so will catch exactly the same geostationary satellites every time!
14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME | 
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| PK 59-18.1 or Abell 72 is a planetary nebula in Delphinus. I can't find any distance estimate for it. There's a tight pair of possibly interacting galaxies just below it. The barred spiral is MCG +02-53-005. I can't find any catalog entry for the small spherical one above it. The other "major" galaxy in the image, to the west, is 2MASX J20493655+1335042. It is blue yet a strong IR galaxy. This is because it is likely forming stars like crazy in the core which is hidden by dust. That dust is heated by the intense stars being formed deep inside it. This causes it to shine strongly in IR light. The blue color indicates star formation is going on strongly in less dusty areas as well, though again, the very newest stars are likely hidden behind the dust clouds that gave birth to them and they too will glow in IR light. Slightly older ones have thrown off their dust veils giving the galaxy its strong blue color.
Odd how I can image a planetary and then talk about field galaxies. I can't find much on this particular planetary so had to say something.
14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME | 
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PK59-18.1L4X10RGB1X20X3R-800-150.jpg
| Abell 78 AKA PNG 081.2-14.9 and PK 081-14.1 (among many aliases) is a blue planetary nebula in eastern Cygnus. The only distance estimate I found for it puts it some 700 parsec's from us +/- 125 parsecs (2300 light-years +/- 400 for the parsec challenged). It's usually imaged in narrowband using OIII and H alpha. Since most of its light is OIII and I don't currently have that filter I stuck to pure LRGB imaging. I found the H alpha so weak it barely showed in the red data. Certainly adding no red to the final image. Papers indicate it is interacting with the interstellar medium it is flying through or is the medium flying through it? This may account for its squashed shape of the OIII ring. Other papers say the core region is severely lacking in Hydrogen but the outer regions have a normal level. The central star is quite bright compared to the very faint one in Abell 80 I posted just before this.
14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME | 
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| The possible planetary nebula Abell 79 is located in Lacerta. I found three different distance estimates for it, 5800, 4200 and 3250+/-500 light-years. This shows how difficult determining the distances to these objects is. Even more confusing is that this page about the Keck telescope considers it a "Planetary Super Nova Remnant" http://www.aloha.net/~joel/keckphot.htm (scroll down half the page). Except for that reference all others I found call it a true planetary nebula which is the outer shell thrown off as a dying star turns into a dead white dwarf. A supernova remnant would create a neutron star or black hole (if it doesn't destroy the star entirely) which is a much denser and smaller object. So I decided to see if I could find anything on its central star and came up with this paper: https://academic.oup.com/mnras/article-lookup/doi/10.1093/mnras/sts180 It lists the central star as spectral type F0V. That means it is a main sequence star like our sun just somewhat more massive and therefore hotter and bluer but certainly not a white dwarf or neutron star. That means it isn't the star that created the nebula but could be a less massive companion that hasn't yet lived out its life. Its light is masking the true central star if it is there and therefore a true planetary nebula. Finding only one reference calling it a planetary SNR I'll go with true planetary though it does appear rather strange for one. The companion may have influenced its appearance, however. F stars normally wouldn't have the needed UV light needed to cause the nebula to glow so I doubt it is the source of the nebula's emissions assuming the F0V classification is correct. That normally requires an O or B star. So it is either ionized by a hidden small but very hot object (white dwarf or neutron star) or is energized by the shock wave created when the expanding shell hits the interstellar medium as is seen in the Veil and similar SNRs.
14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME | 
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