I occasionally like to change my observing program from catalogues like the Messiers or Herschels to double stars, red stars or dark nebulae, just to do something different. This month I'll look at that staple of great Hubble images - planetary nebulae. I'll provide a list of fifteen planetaries that will be in our skies over the new moon this month. Some are familiar, others somewhat obscure, some challenging, some easy. We'll begin in the west and work east in R.A.
08 54 12.0+08 55 00.0Cnc16.812.2
Start with one of the more challenging planetaries - Abell 31. It is described as a huge, faint, roundish glow visible easily with averted vision when using an Oxygen III (OIII) filter at lower power (try at 80x to 100x). Its edges are ragged, uneven, its surface brightness also uneven. Abell 31 is conveniently located between a good group of naked eye stars in Cancer at its border with Draco, near the Dragon's head. Find mag 3.3 Epsilon Hydrae, mag 3.1 Zeta Hydrae and mag 4.1 Alpha Cancri. Abell 31 (PK 219+31.1) sits almost equidistant from each star.
10 07 00.0-40 26 00.0Vel1.48.2
I remember years ago, Jack Zeiders, then president of the SJAA, coming down from the 30" Challenger at Fremont Peak, excited at seeing the Eight Burst Planetary NGC 3132. It is a challenge for us due to its declination. At -40.26 it requires a good southern horizon and steady skies. It is the premier deep sky object in Vela, the Sail. Located in a star poor area of the constellation, this planetary has an apparent central star shining at mag 10, but that is not the star that created this object. its mag 16 dwarf companion is responsible. The object itself has an oblong shape but that does not explain why it is called "Eight Burst". This object is worth hunting down.
10 24 48.0-18 39 00.0Hya0.678.6
One of the brightest planetary nebulae I've viewed is NGC 3242, or the Ghost of Jupiter in Hydra. About half the size and brightness of the planet for which it is named, this target can be seen even in small telescopes. Glowing bluish-green (as do many compact planetaries), it is slightly elliptical and of even brightness. Some report a dim haze exterior to the bright main disk. Can you see it? It has been reported in 6 inch telescopes. How about its central star? One report calls it easy at 300x. There are also some bright knots reported at higher powers and using a UHC filter.
11 14 48.0+55 01 00.0Uma3.3711
The Owl Nebula is among the most well known planetaries, being M97 of the famous Messier Catalog. I have seen it without a filter in my 10" scope on good nights at Houge Park. This is a bright planetary, and an interesting one. Two dark lobes inside the nearly round disc are obvious and enhanced by use of a UHC filter. It is large and has a wonderful neighbor, the galaxy M108 just outside most fields of view. It is easy to find in Ursa Major, just off the line between mag 2.3 Merak and mag 2.4 Phecda at the bottom of the Big Dipper's bowl.
11 26 42.0-34 22 00.0Hya3.1312.1
Returning to Hydra, there is a planetary known as The Southern Owl Nebula. It is also catalogued as PK 283+25.1 and K1-22. With a 13" telescope it is very faint, but using an OIII filter enhances the view to easy direct vision. At low powers, say 80x, it is nearly round, has crisp edges and an even surface brightness. If you find an image of this target, you'll see that it is easy to tell why it is referred to as the Southern Owl Nebula.
12 33 06.0+82 34 00.0Cam0.311.6
Now that we've visited one object named after another, why not do it again. The Eskimo Nebula in Gemini is still visible, but did you know about the Baby Eskimo? IC 3568 is, well, is it a planetary, or not? It is a planetary, but it has been mistaken visually for a compact galaxy, even in some catalogues. This planetary has a high surface brightness, and is located in Camelopardalis above the open bowl of the Little Dipper. It is a small planetary with little obvious color. 5 arc seconds away is a star that makes the planetary appear to be part of a tight double star. IC 3568 is a famous Hubble photo reminding me of the inside of a lemon cut between its ends. Gorgeous. It has been described as morphologically the simplest of planetaries but the Hubble photo tells the real story. A complex inner structure is obvious. It has a sharp edge, brighter middle, and easily visible central star.
Here is the list of 15 planetaries. I hope you enjoy them: the easy ones and the challenges.
| ObjectID||R.A.(h m s)||Dec.(d m
|PK 245+1.1||08 02
30.0||27 42 00.0||Pup||0.12||14.2 |
2610 (Turtle Planetary)||08 33 24.0||16 09
|PK 254+ 5.1 ||08 40
42.0||32 23 00.0||Pyx||0.18||11 |
2.1 ||08 53 30.0||40 04 00.0||Vel||0.33||13
|Abell 31||08 54 12.0||08 55
|NGC 2818A||09 16
00.0||36 36 00.0||Pyx||0.6||11.9 |
238+34.1||09 39 06.0||02 48
|PK 248+29.1 ||09 45
36.0||13 10 00.0||Hya||4.68||12.9 |
|NGC 3132||10 07 00.0||40 26 00.0||Vel||1.4||8.2 |
|NGC 3242||10 24 48.0||18 39 00.0||Hya||0.67||8.6 |
|NGC 3587||11 14 48.0||55 01 00.0||Uma||3.37||11 |
|PK 283+25.1 (Southern Owl Nebula)||11 26 42.0||34 22 00.0||Hya ||3.13||12.1 |
|NGC 4361||12 24 30.0||18 47 00.0||Crv ||1.33||10.9 |
|IC 3568 (Baby Eskimo)||12 33 06.0||82 34 00.0||Cam ||0.3||11.6 |
|Abell 36 ||13 40 36.0||19 53