(This article originally appeared in the Q4 1999 STAR newsletter. -Ian)

Indulgence in Obscurity
by Eric Honeycutt

The following is a scenario that I would like to present and see if it sounds at least somewhat familiar to you: It is a Saturday evening in late January. Temperatures are hovering around freezing and Greg Fishel promises that skies are going to be “clear as a bell”, dew points and humidity are going to be extremely low, and water vapor imagery shows a large, black “hole” over NC. Your SCT is calling your name from the garage while your spouse willingly tells you to “go ahead” while out of the blue, gives you a brand new Tel Vue 35mm Panoptic as a mere “gift of love” (go with me here). A situation such as this is considered a rarity (to say the least) but even under such ideal conditions, there are some out there who would still think twice about going out to observe. Why? When you look into your coming night’s future, what do you see? M42, M42, M31, maybe The Double Cluster and a few bright NGCs? Do you anticipate a night of advancement into this wonderful hobby (lifestyle) or are you planning on well, idling in the same objects you have observed too many times? Sure, these objects do warrant repetition but do you feel yourself possibly losing the slightest amount of interest simply because all that you might think this hobby (lifestyle) has to offer is fainter and less detailed objects than the ones you might be overly-familiar with? I am here to say that if it hasn’t happened yet, more than likely it will to some degree. If this persists, you will find yourself just looking blankly into the sky after a mere few hours of observing, wondering what else there is worth pursuing and you can think of nothing exciting! Suddenly you realize that the motivation you had as beginner is fading. Now, a warm bed and sleep begin to really sound good as the cold, damp, heavy dew, and high humidity of a partly cloudy night envelop you. But now you have to spend fifteen to thirty minutes (or longer) taking down the equipment and packing the car. Another hour later you arrive at home and you realize that you didn’t sample any new objects at all and wonder why you even bother. Sound familiar?

I use to be there. That was until I realized that if you do a little research, you can find some fantastic objects up there that show as much, if not more detail than many of the well-known NGCs and yes, even Messiers. If you know anything about me, you know that I will pull up some objects in my 22″ that are quite obscure. Names like Perek-Kohoutek, Sharpless, Minkowski, Hickson, Abell, Arp, Semeis, Brochum, Mellotte, and Dolidze-Dzimselejsvili are common entries in my observing logs. Once I actually started observing some lesser-known NGCs’, ICs’, and some of the obscurities mentioned above, I immediately found that there were some great objects up there worthy of attention. Not only that, I was utterly amazed that I had never read nor heard about many of these great objects from S&T, Astronomy or astro-aquaintences. Suddenly, a sense of excitement and purpose began to accompany my astronomical pursuit and I could honestly say that I looked forward to every single clear night I could get out and yes, this was still with an 8″ f/6 Meade Starfinder, not a 22″ f/4.1 Starmaster. Thus, I want to share some of these gems with you.

I am going to present a list of my winter favorites that you may or may not have heard of. All should be in reach of an 8″ telescope but they do require “Big Woods skies” or preferably, darker to reap the best views. Also at the end of this article, I will post some “challenge objects” that should test even the most seasoned veterans. I would also like to hear of your observing reports if you do go after some of these so please e-mail me or post them on the RAC website. If you are someone who is starting to experience “astronomical burn-out”, hopefully this list will help motivate you. This will be a relatively long and detailed list to keep you nice and busy until the Spring sky arrives at a decent hour in a few months.

First, lets start in a constellation well known for deep sky objects (in which I will now abbreviate by “dso”) especially open clusters and faint nebulae, the constellation of Cassiopeia the queen. To start things out easy and to hopefully motivate pursuit of the “Herschel 400”, I chose some objects from the list to wet your appetite. Awhile back when nebula filters were starting to become popular, I bought a UHC filter. One of the very first objects I used this particular narrowband filter on was NGC 281. This Emission Nebula/Open Cluster was surprisingly bright haze enveloping a loose open cluster (actually 2 clusters are associated; the other is IC 1590 so you can bag an IC object as well). The nice thing about this emission nebula is an obvious dark notch within the nebula but it will take a UHC or O-III filter to spot. The notch is wedge-shaped and is quite a treat in 12″ or larger instruments as “horns” extend from the dark nebula. NGC 281 is an easy find as it is just 2 degrees NW of Schedar (Alpha Casiopeiae).

The next object we shall look at is IC 1747. One thing that I was amazed to discover when I was advancing through my beginner phase was the number of IC objects obtainable in my 8″ scope. IC 1747 is one of them. This is a planetary nebula that requires an O-III or UHC filter to be seen well. It is an easy find as it is 30″ SE of the 3.4 magnitude star Epsilon Cassiopeia. The PN is 13″ in diameter which means it is not stellar unless viewed at low power. I suggest you use the blinking method with your nebula filter to find it if you have trouble locating it. It should not be difficult as its visual magnitude is 12.1.

Keep that narrowband filter on and go to NGC 896. This 20′ x 20′ nebulous patch is a relatively bright, oval glow but might be difficult without a UHC or O-III filter. Try to notice a dark lane in the nebula. If you notice a slight division, the other side of the division is actually IC 1795 and should be visible under dark, transparent skies. These two nebulae are a great sight for large aperture scopes as a plethora of dark nebulosity can be glimpsed within the glow of the emission nebulae with a UHC or O-III employed.

Our next gem in the queen is the beautiful and rich open cluster NGC 457 so you can take that nebula filter off now. Lying at 9300 light years away, this object is easily found by when you find the gorgeous double star, Phi Cassiopeiae (its membership with the cluster is not known for sure). The double is a yellow and blue star with the separation of 134″ and lies to the SE edge of NGC 457. The cluster has roughly 50 stars visible within the 8″. The concentration is moderate with arcs and chains of stars curving through the middle of the cluster from either side of the double star.

Next is NGC 7789, a magnificent open cluster of several hundred 11th magnitude and fainter stars. It lies 5900 light years distant and is estimated to be 2 billion years old., very old for an open cluster but young for the more populated globular clusters. It is amazing that Messier never included this one into his original list or his predecessors who later expanded the list to 110 objects. The great thing about observing this OC is how it’s thick concentration of stars disperses outwards into a rich, surrounding starfield. It may be hard to determine where this one ends because of all the stars encompassing the halo. The center of the cluster in an 8″ in an unresolved haze.

Our last object in Cassiopeia is another fine open cluster. NGC 663 is a grand assemblage of stars. The cluster is quite rich and beautiful in 16′ of space. 80+ stars make up this cluster and there are 3 labeled double stars in the cluster as well (Sigma 151, 152, and 153). For added detail, see if you can notice the dark streak running through the center of the cluster.

Now, lets go south a little ways into the hero, Perseus. This constellation contains such favorites as the Double Cluster, M76, M34, and The California Nebula. But there are many more objects that many amateurs are unaware of. Since you still have that nebula filter off, lets take another look at a great open cluster, NGC 1245. This rich cluster is a splash of 80 stars in a 10′ area. For detail, you will notice short star chains and arcs throughout the cluster. Very nice.

Now back to the nebula. One of my favorite objects in Perseus is the emission nebula NGC 1491. It is often overlooked unless you are someone who thinks that you are about to be responsible for a bright comet discovery because this dso looks exactly like a comet! So before calling CBAT, make sure you know it is not this neat little nebula. An 8″ will show a bright, fan-shaped glow resembling a stubby-tailed comet. For detail, look for tapered edges at the end of the “tail”.

Keep on the nebula filter and lets go for another IC planetary nebula. This one is IC 2003, a 7″, 12.5v magnitude disk. Now, since this one is only 7″, blinking with a nebula filter becomes necessary unless you already know exactly where to look. Once you blink the nebula into confirmation, use 200x or higher so that the stellar image turns into a disk. Once you see the PN as a disk, see if you can detect the 13.5 magnitude star which is just 15″ to the SW.

Our next dso is a new object for this list. It is a reflection nebula and its designation is NGC 1579. It is a medium brightness glow that is oval in shape. For the beginners, a nebula filter does not help the observation of reflection nebula; it hinders the observation because reflection nebulae are nothing more than reflected starlight off of a dense cloud of molecular hydrogen and dust (this gas and dust is nothing more than dark nebulae; it’s just that now we can see the dark nebula because of a nearby or embedded star). Emission nebulae actually emit their own light when hot young O and early B-Type stars excite the surrounding local gas clouds through ultraviolet radiation, hence causing the ionized gas to fluoresce. Nebula filters highlight the excited gas (note: narrowband filters simply allow the wavelengths of light indicative to emission nebula to pass while severely limiting all other wavelengths; the only way a filter would work for reflection nebula would be to invent a “starlight filter” that blocks out all light other than the wavelengths indicative to starlight – a concept that is currently being researched for the possible advent of a filter specifically designed to see faint central stars in planetary nebula while blocking out the nebulosity that surrounds that central star). Back to our object, see if you can detect a fainter, nearly separated glow to the west of the main oval nebula. This is not a separate designation since the nebula is not actually divided. Detail can be glimpsed but since we cannot take advantage of a narrowband filter, dark skies become absolutely imperative.

Our next stop is a quick turn off into Monoceros, the unicorn. Though many great objects lie here like M50, NGC 2337-39 ( The Rosette Nebula and associated cluster) and NGC 2261 (Hubble’s Variable Nebula) and some great NGC open clusters, I want to simply point out a planetary nebula with a conspicuous central star that is also variable in nature. This PN is is NGC 2346 (Minkowski 1-10). An 8″, an O-III filter, and power over 175x will help you see this greenish-grey PN as somewhat box-shaped instead of circular or amorphous which is peculiar to so many planetaries. The central star varies in magnitude from 11.3 to 13.5+ but is usually visible at high power when seeing is steady (don’t forget to remove the O-III to see the central star if it is not readily apparent with the filter employed).

Speaking of prominent central stars in conspicuous planetaries, I now introduce NGC 1360 for those who may have never heard of this one before. We have to jump far into the southern hemisphere, namely the constellation of Fornax the furnace. There is a planetary nebula so large and so oblong, one could easily mistake it for a galaxy with a prominent stellar nucleus. That stellar nucleus is actually a central star with the super-bright magnitude of 10.9. The nebula itself is a whopping 9’x5′ monster (huge for a PN!). Larger apertures show dark streaks and subtle uneven texture within the nebula. This one is always a surprise when first observed and a pleasure to observe.

Have you ever observed an extragalactic globular cluster? This is a globular that is associated with another galaxy other than our own. There are quite a few visible in M31 and M33 that aren’t too difficult to track down but will require some time to find initially. There is also NGC 2419, also called the “Intergalactic Wanderer” but this is a globular currently believed to once have been apart of our galaxy. However, with its current distance of 300,000 light years away from our solar system (out beyond the Magellanic Clouds) and has a true space velocity greater than our Milky Way’s escape velocity, obviously the globular has been shoved away from us and is traveling into the interstellar voids between the galaxies. Yet, the globular that I present here is NGC 1049, still in Fornax is truly a member of another star system. It is associated with the Fornax Dwarf System which will be invisible to most amateur instruments so don’t bother hunting for it in an 8″ scope. At visual magnitude 12.6, its not hard to get excited knowing that you can observe an extragalactic globular but beware, the surface brightness is lower than 12.6 and can be faint in an 8″ (yet bright enough to warrant its own NGC designation). Make sure you are under dark skies and observe this object when it transits across the meridian. With a little patience, it is rather easy when you know you are observing it. Good luck!

Speaking of globulars, get ready for a show stopper! We are going to go east from Fornax but stay very low in the sky. There is a constellation bordering Lepus and Canis Major called “Columba”, the dove. Many do not realize that there is a deep sky splendor there so large, so bright that if it were just 10 degrees north in declination it would surely be Messier 111. The globular is NGC 1851. This is a beautiful globular cluster that is often overlooked because of its obscure location. You will need a very low southern horizon (Big Woods will do) and catch this on the meridian and you won’t be dismayed. The object has a bright, condensed core that is unresolveable in an 8″. However, the outer periphery is laced with many 10th and 11th magnitude stars. Larger scopes show a mostly-resolved core and very bright individual stars all around the edge of this fine globular. I will check this one out at The Winter Star Party later this month and update my notes.

Going northeast into Canis Major, there are a few bright nebulae that are worthy of your attention. The first is NGC 2359 also known as “Thor’s Helmet” or “The Duck Nebula.” This one and many other bright nebulae are often overlooked because of the many open clusters Canis Major has to offer. A UHC filter or O-III will help this object greatly. In smaller apertures, this emission nebula resembles a duck’s head and bill (larger instruments show detailed extensions and a wealth of detail). Definitely put this one on your list, you won’t be disappointed. Another bright nebula lies close to NGC 2359 and it does not have a NGC designation. Rather, it is from the Sharpless catalogue: Sharpless 2-301. A narrowband filter is a necessity for this one, preferably an O-III filter. An 8″ will show a faint but triangular glow 6′ to 8′. Several stars are embedded in the nebulosity, one of the brighter objects from the Sharpless Catalogue. An open cluster worthy of a observation is NGC 2362. It is easy to find because it surrounds the 4th magnitude Tau Canis Majoris. It is a rich, compact cluster. The cluster lies out at about 5,000 light years and its diameter is roughly 8 light years across. Tau Canis Majoris is the brightest member of the group (yes, believed to be a true member). The observation will prove to be rewarding as the cluster is very bright, rich, and large in diameter. Tau CMa is truly odd being so bright.

Over to Puppis, the ship’s stern now for a nice emission nebula and open cluster: NGC 2467 (also known as Sharpless 2-311). The object is an easy, oval glow with a UHC or O-III filter, even in a 5″ scope. Internal darkening is discerned even in a 5″ but with more certainty in larger instruments. Also, larger apertures show outer areas of nebulosity not apparent in scopes under 10″. Nice surprise. Also in Puppis, there is a nice planetary nebula that also might be overlooked. NGC 2440 is a medium-sized planetary (32″) who’s greenish, oval disk is readily apparent at powers over 175x. The magnitude is an easy 9.4 visual magnitude so it shouldn’t give you much problem. Of course, you should always check out the beautiful planetary superimposed over M46 while you are in Puppis but most have heard of this object so I won’t devote the time.

Now, you may be wondering why I haven’t gone to Orion yet. Well, there are so many bright NGC’s and of course, the famous Messiers that are known because of the popular constellation and/or the objects are listed in the Herschel 400. Thus, I am not going to analyze any particular object except to briefly list a few favorites. These objects include NGC 1973-75-77, NGC 2024, NGC 2023, NGC 2022, IC 434 and Bernard 33 (The Horsehead), and NGC 2174. All are worth observing but even though all are visible in an 8″ scope, most of these require 10″ or larger instruments to discern appreciable detail.

I hope I have offered some objects that are a little more off of the beaten path. These objects are not just faint fuzzies. Instead, I chose these gems because of the detail that can be glimpsed under good conditions. We have a few months to observe these deep sky objects so don’t feel as if you have to observe them all in one or two nights. They are to be absorbed slowly, like a fine glass of wine. I want to hear about your observations so please post them on the RAC website. Here are the data for all the objects listed above to make the hunting easier:

Object Cons  Type  Mag Size  R.A.  Dec
NGC 281 Cas EN/OC 7.4p 4′ 00h 52.8′ +56° 37′
IC 1747 Cas PN 12.1v 13″ 01h 57.6′ +63° 20′
NGC 896 Cas EN/OC Ph Br 1-5 20 ‘x 20’ 02h 26.5′ +62° 04′
NGC 457 Cas OC 6.4v 13′ 01h 19.1′ +58° 20′
NGC 7789 Cas OC 6.7v 15′ 23h 57.0′ +56° 44′
NGC 663 Cas OC 7.1v 16′ 01h 46.0′ +61° 15′
NGC 1245 Per OC 8.4v 10′ 03h 14.7′ +47° 15′
NGC 1491 Per EN Ph Br 1-5 25′ x 25′ 04h 03.4′ +51° 19′
IC 2003 Per PN 12.5v 7″ 03h 56.4′ +33° 52′
NGC 1579 Per RN Ph Br 1-5 12′ x 8′ 04h 30.2′ +35° 16′
NGC 2346 Mon PN 11.8v 60″ x 50″ 07h 9.2′ -00° 48′
NGC 1360 For PN 9.4v 9 ‘x 5’ 03h 33.3′ -25° 51′
NGC 1049 For GC 12.9v 0.4′ 02h 39.7′ -34° 17′
NGC 1851 Col GC 7.2v 11′ 05h 14.1′ -40° 03′
NGC 2359 CMa EN Ph Br 2-5 9′ x 6′ 07h 18.6′ -13° 12′
Sh2-301 CMa EN Ph Br 1-5 8’x7′ 07h 09.8′ -18° 29′
NGC 2363 CMa OC 4.1v 8′ 07h 18.8′ -24° 57′
NGC 2467 Pup EN/OC Ph Br 1-5 16’x12′ 07h 52.5′ -26° 24′
NGC 2440 Pup PN 9.4v 32″ 07h 41.9′ -18° 13′

Listed below is my challenge list. Some of these objects should not be attempted if you are pregnant, have heart problems, or cannot handle intense levels of stress. Good luck!

Eric’s Challenge Objects:

The following objects are for die-hards with keen eyes, good skills, and apertures over 12″:

IC 423 Reflection Nebula in Orion
IC 426 Reflection Nebula in Orion
Bernard’s Loop Hold 2″ O-III filter up to your eye in very dark skies to glimpse this very long nebula.
Abell 10 Planetary Nebula in Orion
Abell 12 Planetary Nebula in Orion (just 2′ wnw of mu Orionis)
Minkowski 1-18 Planetary Nebula in Puppis
Abell 22 Planetary Nebula in Gemini – “The Medusa Nebula”
IC 443 Super Nova Remnant in Gemini – “The Winter Veil”
Semeis 147 Super Nova Remnant in Taurus
IC 405 The Flaming Star Nebula
Sharpless 2-221 Super Nova Remnant in Auriga
Sharpless 2-216 The Closest Known Planetary Nebula (Retinal torture)
IC 1613 Dwarf member of Local Galaxy Group (Large apertures in ultra-dark and steady skies may reveal individual stars within this close but faint galaxy).
Jones-Emberson 1 Large Planetary Nebula in Lynx