(This article appeared in the Q1 2000 STAR news letter. -Ian)
An Indulgence In Obscurity – Part II. The Spring Sky
by Eric Honeycutt
Finally, Spring is here! After a winter that brought record snowfall and quite a few cold observing sessions, the Triangle is beginning to warm up. The birds are singing, the flowers are blooming, the grass is growing and greening up, um…the pollen count is rising, the humidity and dew are getting heavier, and there has been constant rainfall and cloud cover for the last few weeks….aauugh! What’s there to look forward to in early Springtime? Well, when a clear night does present itself – many wonderful deep sky objects, that’s what! I am going to take you on a tour of some lesser known deep sky objects (“dsos” for short) within the Spring sky. Some of these objects you may have heard of or even observed. Others might be totally new. Whatever the case, all should be visible with an 8″ scope under dark and transparent skies. Some will show a plethora of detail while others will be just on the threshold of vision in 8 inches of glass (note: an aperture of 8″ is my standard for the majority of this article). The point of this article is an attempt show you that just because you may not have heard of certain objects does not mean that they are uninteresting and/or unobservable. In fact, my favorite objects that show great amounts of detail are mostly non-Messier. The following article will focus on many galaxies (of course, its Spring); but instead of giving you a lot of single galaxies to hunt for, I want to show you objects that are a little more on the exotic side such as: a galaxy cluster that many do not know about in Hydra; many physically-interacting galaxies; a few galaxy groupings from the Hickson catalogue; and this article just wouldn’t be complete without some rather obscure planetary nebulae that are hiding behind some vernal constellation. I hope you can get out and hunt down some of these dsos at our Big Woods site, at Morris Observatory or better yet, under the very dark skies of the Virginia or North Carolina mountains. At the end of my article, I will list a few of my “Challenge Objects” for the big guns and/or the serious die-hards out there. Please tell me of your exploits if you so dare to take the challenge.
We will begin our quest with a galaxy cluster. No, not the Virgo or Coma clusters. Rather, we are going to Hydra and observe Abell 1060, also known as “The Hydra 1 Galaxy Cluster.” Lying at 200 million light years, how many cluster members you see will of course, depend on the size of your instrument and how dark and transparent your skies are. In an 8″ scope, there are four, five, possibly even 6 that should be evident. In a 16″ or larger scope, as many as 8 are present in a 1/4 degree field. The members include NGC 3305, 3307, 3308, 3309, 3311, 3312, 3314, and 3316. NGC 3311 is the brightest at 10.9 visual magnitude while the dimmest member glows at a feeble 14.2 visual magnitude. Faint stellar nuclei can be glimpsed in the brighter members. Coordinates for the brightest member are: 10h36.7′ -27°32′. Next we go to Leo for another galaxy grouping, though it is not considered a cluster (in itself) as Abell 1060. This one is called Hickson 44 (taken from the Hickson Catalogue of Compact Galaxy Groups) and it can be found midway between the beautiful double star gamma Leonis and Zeta Leonis. The grouping consists of 4 galaxies: NGC 3185, 3187, 3190, & 3193. 3 are easily visible in an 8″ scope while the faintest, NGC 3187 might be beyond reach. NGC 3190 is a peculiar spiral galaxy that reveals a dust lane and a stellar nucleus in larger scopes. The entire grouping may be evident in an 8″ scope but you will need nearly perfect conditions. Magnitude and coordinates for the brightest member are: 11.2V and 10h18.1′ +21°50′.
Staying in Leo, we will turn next to NGC 2903. A large and bright SAB galaxy that can even be seen in a 3″ scope (and possibly smaller). A mottled halo surrounds a strongly condensed core with a bright stellar nucleus. Dark “areas” can be glimpsed on really good nights with a 6″ or 8″ scope. This 9.0V magnitude galaxy is nearby at roughly 31 million light years away but surprisingly, it is not a member of the local group. Coordinates are 09h32.2′ +21°30′.
On to Leo Minor, we go after an interacting pair of galaxies that are very beautiful in my opinion. The pairs are NGC 3395 and 3396. Both are of the same visual magnitude at 12.1 but the Surface Brightness (SB) on NGC 3396 is 13.6 (the SB on NGC 3395 is 12.3). The two galaxies touch each other at their tips giving the appearance of a butterfly or bird with a large wingspan. NGC 3396 has a stellar nucleus in larger scopes where NGC 3395 has a broader yet, nonstellar nucleus. The coordinates to this fine galaxy pair are: 10h49.9′ +32°59′.
While we are on interacting galaxies, lets go south for a real show stopper. NGC 4038 and NGC 4039, also known as “The Ring Tail Galaxy” is impressive enough for even 6″ scopes to see detail. These two 10.5V magnitude galaxies have advanced much farther than NGC 3395 and NGC 3396 as they are well into their collision state. The bizarre dso takes on the shape of a “C” and its shape has been compared to that of a shrimp with NGC 4038 being the head and 4039 being the tail. Dark patches can be seen in 4038 as well as 4039 and a separation can be discerned. Knowing that this dso is really two galaxies, the observer automatically knows that there has been a great transformation from the two galaxy’s original state. Long exposure photographs show clouds of material that surround the outer two lobes. These clouds are stars that have been thrown several thousands of light years from their host galaxy. Larger instruments hint of this “pseudo-halo” under ideal conditions. Coordinates are: 12h 01.9′ -18°52′.
Leaving galaxies for a second and returning to my kind of dso, Corvus offers a nice little planetary for medium sized scopes. NGC 4361 near the center of the keystone shape of Corvus, has a nice Central Star that shines at Visual Mag 13.18 so if you are using a 6″ or 8″ scope, be sure to remove your O-III or UHC filter to see the Central star. Adding power really helps as well to see the central stars of planetaries. The Pn’s color is grey and it is fairly bright shining at a respectable 10.9V magnitude. Apertures at 12″ or over begin to dissect two concentrations within the Pn itself. Nice object. Coordinates are: 12h24.5′ -18°48′.
Up to Virgo now for another lesser-known planetary. This one is IC 972, also known as Abell 37. While it has a photographic magnitude of 14.9, one should not be too timid about trying this one. Photographic magnitudes for planetary nebulae are dimmer than visual magnitudes, sometimes by two whole magnitudes. The reason? Photographic imaging is weak in the two main emission lines indicative to planetary nebulae (500.7nm and 494.9nm). Fortunately, the human eye is most sensitive to these wavelengths. Thus, when one sees a very dim photographic magnitude for a planetary, do not choose not to observe it. You may be pleasantly surprised as I hope you are in this case. I will say that this one will be a bit faint but its surface brightness is relatively high. Use an O-III filter under dark skies and you just might find a small, circular planetary just 7 degrees or so SW of Kappa Virginis. Blinking your O-III might become necessary once you identify the correct field. My 22″ shows this planetary as a neatly round, grey disk with no features. The central star is a very dim 17.9 magnitude. This is considered a challenge object but keen eyed observers should be able to find it in an 8″. Coordinates are 14h04.3′ -17°13′.
Now, lets stay in Virgo and go for a classification of dso that isn’t observed too often. 3C 273 QSO is the brightest quasar found in the sky. At a blinding 12.8v magnitude, this blue/white pinpoint could easily be mistaken (hence, overlooked) as a star. In fact, it might be difficult to find because it lies just 50″ east of a 12.9 magnitude star. A Scorpius-like star pattern lies in the same field. Use a good star map to make sure that you are identifying the correct object. Coordinates are: 12h29.7′ +02°03′.
Next we move north again into Coma Berenices for just one dso. Here lies the grandfather of all edge-on spirals, NGC 4565. Lying at 31 million light years, it is one of the brightest members of the Coma1 Galaxy Cloud (I am not referring to the more distant Coma/Virgo Cluster which lies at 400 million light years away). This edge-on spiral will show you good detail that can be seen in an 8″ scope – all you need are the dark skies! This SA type galaxy has a very prominent dust lane that is visible without averted vision if you have good eyesight. See if you can spot the 13.5 magnitude star lying 1.5′ NE of the central bulge. The larger the scope, the more detail you can see within the dust lane. Large scopes reveal notches all along the dust lane that resemble a spinal column. High power in a large aperture scope and steady seeing are a prerequisite for noticing this intriguing feature. Coordinates are 12h36.3′ +25°59′.
Further now in the north we go into the Hunting Dogs, Canes Venatici. Many wonderful dsos reside here including some more interacting pairs of galaxies. The first pair is Arp 269. The interacting pair are NGC 4485 and 4490 and they are located just 42′ NW of Beta Venaticorum. The larger and brighter companion, NGC 4490, shines and a relatively bright 9.8V magnitude and it is called “The Cocoon” because of its teardrop or cocoon shape. However its surface brightness is around 13 so it won’t be as bright as 9.8 magnitude implies. NGC 4485 is 11.9V magnitude but has a low surface brightness of 13.8. The shape of the pair is very similar to the two galaxies in Leo Minor and will be a treat for anyone who wishes to hunt them down. Coordinates are 12h30.5′ +41°42′.
Staying in Canes Venatici and staying with the interacting galaxy concept, we look to our second interacting galaxy pair. Now, I want you to think “Hurricanes”. Not the weather phenomenon rather, the hockey team. Why? NGC 4656-57 – The Hockey Stick. This very long edge-on takes the shape of a hockey stick and lies only 30′ from NGC 4631, another very long and impressive edge-on galaxy in which one must observe while in the vicinity because it is truly an awesome dso and guess what, another interacting pair (NGC 4627 and 4631). The texture to NGC 4656-57 is mottled with several bright condensations but no stellar nucleus. It shines at 10.5V but its surface brightness is a feeble 14.8. Dark and transparent skies are certainly needed to see good detail in this one. In fact, the smaller companion may be really faint if your skies are anything less than ideal. The pair is truly a physically interacting pair as is the previous objects we’ve analyzed (note: since we are in Canes Venatici and are talking about interacting pairs, I should point out something that many people are unaware of. M51, a fantastic SA spiral is not interacting with NGC 5195. Actually, NGC 5195 is much more distant but it is still a satellite of M51 thus, it is considered a companion. Just not a interacting one). Coordinates for the Hockey Stick are: 12h44.0′ +32°10′.
Another interesting object in Canes Venatici is the SA spiral NGC 4244. In an 8″ scope, this dso is a very long, bright, spindle shaped galaxy. The visual magnitude is 10.4. Dark and transparent skies are needed to see any mottling texture and or knots but they can be glimpsed if close scrutiny is utilized. Coordinates are: 12h17.5′ +37°49′.
Now, before I finish things up I want to offer some objects that I consider to be challenge objects. Some of the dsos’ I listed above also might fit into this category but nothing like the ones I am about to feature. For some of these dsos, large aperture is needed (14″ or higher) and even then, they might be incredibly faint. First, lets keep going north into Ursa Major. Here we are going to look at a truly exotic object: The Double Quasar. As I am writing this article, I am nestled in the side of secluded mountain at 3400′ above sea level in highlands of southwest Virginia. The skies are very dark here (dark enough for Pierre Faucher and I to observe a 7.6 magnitude star in Ursa Major by naked eye earlier this week). On this same night, we both observed this little challenge object. The magnitude is a feeble 16.5 (actually the Double Quasar is variable in its magnitudes ranging from 16.5 to 17.3) and the separation between the two components are 6″. I was looking for a diamond-shaped asterism that lies less than 30″ to the east. Also, a very large and nicely detailed galaxy, NGC 3079 lies directly to the south so use these two signs as markers. I easily found the asterism and within a few moments, I saw a very faint “star” where the double quasar should be. The object did not appear stellar however, as it displayed a slight “fuzzy” appearance with a strange blue/green hue to it (note: this is peculiar since quasars have incredibly high redshifts). With close scrutiny and higher power of 288x employed, the faint extended object was actually split into 2 components. Splitting the Double Quasar was my objective and I did it. Actually, it wasn’t too difficult. Better seeing would have allowed even higher power. Coordinates for this dso are: 10h 01 21″ +55°54′.
My second challenge object is Copeland’s Septet in Leo. This group of 7 galaxies (also known as Hickson 57) was first observed by Ralph Copeland, an assistant to Lord Rosse whose mammoth 72″ telescope was first responsible for detecting the now misclassified “spiral nebulae” (later determined to be galaxies, of course). This challenge object consists of all NGC galaxies: NGC 3745, 3746, 3748, 3750, 3752, 3753, & 3754). NGC 3753 is the brightest member at 13.6V magnitude while NGC 3745 is the faintest at 15.1 magnitude. I cannot stress enough how important very dark skies are for objects such as this. You will need the stark contrast for all 7 members but it can be done. Utilize patience and drape a dark towel over your head to block out all extraneous light (sometimes you can see a magnitude fainter if you employ this nifty little trick). Your reward will be your success in observing this tough dso. Coordinates for NGC 3753 are: 11h 37′ 54″ +21° 59′.
Next we look at a very dim planetary in Coma Berenices. This is not an area of the sky one would expect to find a planetary nebula. However, there is one here that is quite faint and almost impossible to observe in anything less than a 15″ scope. The designation is: LoTr5 or PNG 339.9 +88.4. Lying between two 9th and 10th magnitude stars, this planetary is a very large (8.8′). Its true central star is near 15th magnitude but a superimposed star of 8.6 magnitude will deter observation of the white dwarf. Thus, the field is not difficult to find since there is a chain of 3 stars of relatively equal brightness. The one in the middle is surrounded by our planetary. In my 22″, I used an O-III and found the planetary after scrutinizing the middle star for a few minutes. I began to notice a faint, circular haze around the star that was not around the two surrounding stars. Low power is imperative (I was at 74x) since the Surface Brightness is so low. Soon I began to see somewhat of an annularity to the round haze that looked like sort of like a doughnut. If you observe this one, you are only one of a handful that ever has visually. Good luck.
My last challenge object is probably the most difficult for this list and considered by The Observer’s Handbook as being “perhaps the most difficult object for amateur telescopes” (published by the Royal Astronomical Society of Canada). It is the Corona Borealis Galaxy Cluster which is also known as Abel 2065. The brightest galaxy listed in this galaxy cluster is a faint 15.3. The reason that this cluster is so difficult is because it is nearly 1 billion light years away. Now, despite the sometimes faulty opinion that low power allows you to see faint objects more easily, I recommend finding the field in a low power eyepiece and then boosting the power up to at least 175x or even 200x. You will need ultra dark skies with very good transparency (similar to what I experienced this past Wednesday night up here in the mountains). Expect to take some time and use patience. If you think that you can go to the eyepiece and see all there is to see in a few minutes, then you are missing out on so much more. Objects like this sometimes take two hours for an extensive and thorough observation. This past Wednesday night, I was able to make out 7, possibly 8 of the brightest members. I found that my 12 Nagler (Type 4) which yielded 216x was the best power on this particular night. No NGC galaxies are involved. The brightest member is PGC 54876 with fainter members going beyond the reach of my 22″. The faintest galaxies that I observed from this cluster were pushing 16.3 magnitude. Not too difficult for stars but galaxies are another story. If you observe this one I definitely want to know about it. I am still a bit stunned that I observed light that has taken 1 billion years to get here. Coordinates for PGC 54876 are: 15h 22′ 18″ +27° 42′.
I certainly hope that you have enjoyed this edition of Indulgence In Obscurity – The Spring Sky. As you can see, there are many fantastic objects up there at this time of year that a deep sky aficionado like yourself can spend countless hours observing. Don’t ever make the mistake of thinking that there is not enough to observe on any given night during any time of the year. I wish I had more time to get out and hunt down objects such as these but I don’t. When I do, it usually is cloudy and/or rainy just as much of this week has been. There is never enough time for this hobby (lifestyle) so when you are under very dark skies as I am now, savor every moment of it!
Recap of Objects. -Ian
| Name | Cons | Type | Mag | R.A. | Dec | Notes |
| Abell 1060 | Hyd | Gal Cl | 14.2 | 10h 36.7m | -27° 32′ | Hydra 1 Galaxy Cluster |
| Hickson 44 | Leo | Gal Cl | 11.2v | 10h 18.1m | +21° 50′ | NGC 3185, 3187, 3190, 3193 |
| NGC 2903 | Leo | Gal | 9.0v | 09h 32.2m | +21° 30′ | SAB Galaxy |
| NGC 3395/3396 | LeoM | Gal | 12.1v | 10h 49.9m | +32° 59′ | |
| NGC 4038/4039 | — | Gal | 10.5v | 12h 01.9m | +18° 52′ | Ring Tail Galaxy |
| NGC 4361 | Cor | PN | 10.9v | 12h 24.5m | +18° 48′ | Central Star is 13.18v |
| IC 972 | Vir | PN | 14.9p | 14h 04.3m | -17° 13′ | Abell 37 |
| 3c 273 | Vir | QSO | 12.8v | 12h 29.7m | +02° 03′ | Starlike Quasar |
| NGC 4565 | Com | Gal | — | 12h 36.3m | +25° 29′ | |
| Arp 269 | Can | Gal | 9.8v | 12h 30.5m | +41° 42′ | NGC 4485 and 4490 |
| NGC 4656-7 | Can | Gal | 10.5v | 12h 44.0m | +32° 10′ | The Hockey Stick |
| NGC 4244 | Can | Gal | 10.4v | 12h 17.5m | +37° 49′ | |
| Double Quasar | UMa | QSO | 16.5 | 10h 01″ 21″ | +55° 54′ | Challenge Object |
| Hickson 57 | Leo | Gal Cl | 13.6 | 11h 37′ 54″ | +21° 5′ | Copeland’s Septet |
| LoTr5 | Com | PN | 15 | —- | —- | PNG 339.9 +88.4 |
| Abel 2065 | Cor | Gal Cl | 15.3 | 15h 22′ 18″ | +27° 42′ | Corona Borealis Galaxy Cluster |
