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Glowing in the Shadow of Grandeur

by kt4hx

The inconvenient truth is that the vast majority of DSOs are not found near brighter stars. Of course such placement would make finding them much easier. However, and I am sure a few would disagree, I feel that would take away the challenge and fun of the hunt. I like challenges, as they make you plan better and work harder to get the rewards, making those rewards all the sweeter.

I have, for quite a few years now had a personal affinity for DSOs that can be found lurking and almost hiding at times in close proximity to brighter stars. In this unique subset of objects I also include smaller and dimmer DSOs that are overshadowed by a showpiece object found nearby. Hence the title I have chosen for this article. These objects sometimes exist in relative anonymity, though a few do gain enough notoriety within the hobby to be given nicknames that are commonly used.

The glare of a brighter star nearby may cause some difficulty in detecting the DSO, thus creating a unique challenge to the observer. In the case of two DSOs lying in close proximity, the larger, splashier one garners the attention of observers, who may fail to notice or even be aware of the nearby object. Sometimes it can truly be a case of being unable to see the trees for the forest. That is why it really pays to study your favorite charts, atlases and/or software during planning. Look for the primary objects of interest to you of course, but also keep an eye out for nearby DSOs that sometimes can lie within the same field of view. These peripheral objects can often be a challenging and rewarding byproduct of diligent pre-observational planning.

In this article I will cover a few such objects that I have observed personally over the years, and some of which have become personal favorites of mine. Rest assured these are not the only juxtaposed DSO/star or DSO/DSO combinations in the sky. However, they do represent a good cross-section of this unique subset of objects and will hopefully trigger your own curiosity about them spurring you to seek out others.

I realize that not all the ones I will present are accessible to all observers, as a few are found at lower declinations. I have been fortunate that I occasionally travel to more southern latitudes as part of my work, and have taken small telescopes and binoculars with me at times. But there should be something here for everyone no matter where they live and no matter their aperture and sky quality. Some are relatively well known and not excessively difficult, whereas some could prove quite challenging and require darker skies with more aperture.

So with the background information laid out, let’s take a look at how objects will be presented. Each section will contain the object of interest with its basic data followed by the nearby star with its standard nomenclature and visual magnitude, plus any traditionally recognized names or alternate identifiers that are useful to the reader.

For those cases where we have a showy and well known DSO pulling one’s attention away from a nearby object of less prominence, then the basic data will be provided for both. The information for the DSOs are extracted from the site Telescopius.com. There are of course various sources for this information, of which this is one that I regularly utilize.

I will also include an annotated image taken from the POSS1 survey for each object displaying the positional relationship between the objects involved. Credit for the images belongs to the University of Minnesota and their Minnesota Automated Plate Scanner (MAPS) Catalog of the POSS I (see endnote). Typically all one need do is locate the position of the dominant star or object in their charts or software and let the fun begin. In some cases where there are wider separations that will be annotated in the images. You will notice some are done in red while others green. The color that gave the best visibility for the shading of the image was chosen. The lines used to indicate separation between objects are mostly from edge to edge for best visibility. While the actual distances listed are center to center between objects. So without further ado, let’s get to the heart of what this article is about, the objects themselves. I hope you enjoy the journey.

Messier 109 // NGC 3992: barred spiral galaxy in Ursa Major; mag=9.8, size=7.5’x4.4’, SBr= 13.3 mag/arcmin^2

…visually does battle with…

Gamma Ursae Majoris: mag=2.44; aka Phad or Phecda

Because this galaxy is found in Messier’s famous list of objects, it is likely the most well known example of a DSO that can at times be challenging due to the glaring from a nearby bright star. Since the majority of us cut our observing teeth using the Messier list before moving on to the larger and more diverse riches of the universe, most are very familiar with this example.

Even with a spacious separation of nearly 39’ to the southeast of Phad, M109 can be a bear for some folks. Particularly if they are using smaller apertures and/or working against a significant light pollution level that weakens the presence of the galaxy. It does sport a fairly bright visual magnitude for this type of object, and will appear as an elongated glow. The key here is trying to move Phad out of the field of view (FOV) by using a combination of magnification and placement within the FOV. While the galaxy can indeed be spotted with Phad in the view, it is easier without the star’s visible presence in the eyepiece.

I have seen this galaxy from various locations using instruments ranging from my 5 inch refractor up to a 17.5 inch dobsonian reflector. The best view I ever had, not surprisingly, was with the largest instrument at our dark site. The galaxy was extremely bright and large visually, with a very strong oval central region set within a diffuse outer halo.

M109 and Phad_POSS1.jpg

NGC 404: dwarf lenticular galaxy in Andromeda; mag=10.3, size=3.5’x3.5’, SBr=12.71 mag/arcmin^2

…visually does battle with…

Beta Andromedae: mag=2.05; aka Mirach

Lovingly referred to as “Mirach’s Ghost” by astronomers, this dwarf lenticular is also very well known to the DSO crowd. It is separated from brilliant Mirach by less than 7’ to the north-northwest. The star shines glaringly bright within the eyepiece and can easily swamp the galaxy’s diffuse round glow with small apertures and low magnification. Nonetheless it is possible to detect the galaxy with careful study. Increasing aperture and magnification simply makes the task a bit easier. Typically the “Ghost” is not a significant challenge, but may require patient study of the field on the part of the observer.

I have observed this diffuse phantasm from various locations in instruments ranging from a 5 inch refractor up to the 17.5 inch dobsonian. It was not difficult from a semi-dark location at low magnification in the 5 inch. However, increasing magnification did boost is visual presence within the view. Generally homogenous in appearance, a stellar core may be noted as aperture increases.

NGC 404 and Mirach_POSS1.jpg

NGC 6441: globular cluster in Scorpius; mag=7.2, size=9.6’, SBr=11.8 mag/arcmin^2, class=III

…visually does battle with…

G Scorpii: mag=3.19; aka HD 161892, Fuyue and formerly Gamma Telescopium

Frankly this object is pretty easy. Though only separated by a little over 4’ of angular distance to the east of G Scorpii, it is bright enough and with an intense compact core, that the star presents little difficulty for the observer. G Scorpii itself is found in the tail of Scorpius. It lies a little over 3° east of Lambda Sco, which with Upsilon forms the stinger of the great celestial scorpion. I truly enjoy the contrast of this pairing and it is one of my personal favorites.

I have seen this object even in 10x50 binoculars and an 8x50 RACI finder. In smaller apertures the cluster is clearly non-stellar, appearing more like a diffuse out of focus star. As aperture increases its real nature become much clearer and it takes a strong presence in the view. The glare of G Scorpii does little to deter the small cluster’s visibility. With larger aperture, the core becomes quite brilliant and the outer halo can become mottled but does not give any resolution of stars.

NGC 6441 and G Scorpii_POSS1.jpg

NGC 6144: globular cluster in Scorpius; mag=9.0, size=7.4, SBr=13.1 , class=XI

…visually does battle with…

Alpha Scorpii: mag=1.0; aka Antares

This is a unique object in that it lies about 38’ northwest of brilliant Antares, and also about 57.5’ northeast of the center of a showpiece globular, Messier 4.So in that regard it deals with both the glaring of the relatively nearby star and taking a back seat to the more impressive DSO not too far removed. Because of the prominence of Antares and the presence of a Messier object nearby, NGC 6144 is frequently ignored or completely forgotten. It truly suffers a double-whammy of indifference.

I have observed it with a 5 inch refractor from a semi-dark location where it was a ghostly apparition in a field dominated by both Antares and M4. With the 10 and 12 inch dobs it starts to become mottled, even giving up resolution of a few stars. But at no time did it command attention given its more prominent neighbors in the field.

NGC 6144 and Antares_POSS1.jpg

NGC 5102: lenticular galaxy in Centaurus; mag=9.6, size=8.6’x2.7’, SBr=12.7 mag/arcmin^2

…visually does battle with…

Iota Centauri: mag=2.73

Now we dive a little farther south and get into the northern portion of the celestial centaur. Located about 7.5° south-southwest of Messier 83 in southern Hydra, this galaxy has earned the nickname Iota’s Ghost, reminiscent of Mirach’s Ghost in Andromeda. NGC 5102 is located just over 17’ east-northeast of bright Iota Centauri, and is popular with southern hemisphere observers where it rises significantly above the horizon.

However, it is within reach of many in the northern hemisphere at its declination of about -36.5°. Obviously it does not rise considerably high above the southern horizon for mid-northern observers, but is still accessible by many provided they have an unobstructed and darker southern view. The glare of Iota can definitely have an impact on this galaxy. But like M109, its magnitude and modestly high surface brightness help it punch through under good conditions.

I have been fortunate to observe this object from various locations/latitudes with instruments ranging from an 80mm refractor up to a 12 inch dobsonian reflector. In the smaller instrument from a suburban area just south of the equator it was very challenging through the prevailing local conditions coupled with Iota’s glare, but still as fleetingly visible as a breath on a mirror. From a semi-dark location at around 18°N latitude with the 5 inch refractor it was an easily seen despite being a faint elongated wisp of light impacted by Iota’s presence nearby. Then at our dark site at around 38°N latitude, I have seen it low on a relatively flat horizon where it reached about 13° elevation. Through the 10 and 12 inch dobsonians it was seen as a bright and fairly large elongated swath of light punching through the glare of nearby Iota, even exhibiting a bright core region. This combo is another of my personal favorites, as is the next duo.

NGC 5102 and Iota Cen_POSS1.jpg

NGC 5286: globular cluster in Centaurus; mag=7.4, size=11.0’, SBr=12.3 mag/arcmin^2, class=V

…visually does battle with…

M Centauri: mag=4.64; aka HD 119834

Deeper into Centaurus at just over -51° declination and about 5° southeast of the stupendous globular NGC 5139 (Omega Centauri), we find another nice star-DSO juxtaposition. NGC 5286 is a bright and medium sized globular that lies about 4’ north-northwest of the modestly bright star M Centauri. Because of its brightness, just like with NGC 6441 in Scorpius, it stands out well in the view with its stellar neighbor. This pairing can be found just over 2° north-northeast of mag 2.30 Epsilon Centauri.

As fortune would have it, I’ve been able to observe this star-DSO combination from a couple of more southern locations using instruments ranging from 10x50 binoculars to a 5 inch refractor. At all apertures I’ve used I found the weaker glare from m Cen to be minimally invasive. As long as one is far enough south, it is easily observed. From about 18°N it was bright with a broadly bright core in the 5 inch refractor. Even from just south of the equator in the 80m it was likewise easy and bright with m Cen not compromising the view in the least. This is simply a very attractive pairing, and I wish it were accessible from home.

NGC 5286 and m Cen_POSS1.jpg

The above objects are a few fine examples of DSOs lurking near brighter stars. Some are pretty easy while some may require just a tad more patience on your part. I enjoy the contrast within the view between a brighter star and a dimmer DSO in close attendance. It is a very curious visual dynamic that I find personally satisfying in the eyepiece.

Now let’s look at a few juxtapositions of more than one type of DSO within, or nearly within the same view. In these cases there is a clearly dominant DSO that garners the observer’s attention. That can sometimes lead observers to overlook the curious contrast with a dimmer and different type of DSO nearby, if indeed they are even aware of its presence. Let’s take a look!

NGC 6207: spiral galaxy in Hercules; mag=11.6, size=3.0’x1.2’, SBr=12.7 mag/arcmin^2
IC 4617: spiral galaxy in Hercules; mag=15.2, size=1.2’x0.4’, SBr=14.1 mag/arcmin^2

…vying for your attention with…

Messier 13 // NGC 6205: globular cluster in Hercules, mag=5.7, size=20.0’, SBr=12.0 mag/arcmin^2, class=V

Here is indeed one of my personal favorite DSO juxtapositions. The glorious and famous Great Hercules Cluster has its own little attendant nearby for those that notice. NGC 6207 is the brightest galaxy in the strongman’s lair, but it doesn’t garner a lot of attention from observers. Though not significantly bright at magnitude 11.6, it certainly is attainable for a great number of observers who know to look for it. It is located about 28’ north-northeast of the center of M13, and just 19’ north of the mag 6.86 star HD 150998 lying just 17’ east of the globular’s core. But let’s face the fact that with the dominance of M13 in the eyepiece, it’s understandable that people would be mesmerized and might not even think there was anything else in such close proximity. It simply is very difficult to tear your gaze away from the real show in front of you and divert your focus to its periphery.

I have observed this spiral with 10, 12 and 17.5 inch dobsonians, from both our suburban and dark site houses. It most certainly would be visible in smaller apertures under good conditions as well. I have found it a convenient indicator of transparency conditions. Since it’s not unusual to take a quick peek at M13 when it is in the sky, one can simply give the galaxy a quick peek as well and get a good handle on transparency conditions.

If you want a true challenge while you are admiring M13, and NGC 6207 was easy for you, then consider IC 4617. This painfully dim galaxy is a significant challenge and requires dark skies coupled with some more serious aperture. It is found just over 14’ northeast of the center of M13 and a similar distance southeast of NGC 6207.
At a seriously dim visual magnitude of 15.2, my only experience with this little sliver of light was at our dark site with the 17.5 inch. Even so, it was no picnic. It took prolonged study of the field and the stars within it, plus pushing magnification to 296x and 422x in order to confirm its presence. Ultimately it appeared as nothing more than a tiny, diffuse sliver with a mag 14.26 field star off its eastern edge and one of mag 15.14 at its northern tip. I only include this for those observers who do have the aperture and conditions for it, and want a serious challenge.

NGC 6207 and M13_POSS1.jpg

NGC 2438: planetary nebula in Puppis; mag=10.8, size=1.3’, SBr=11.0 mag/arcmin^2

…vying for your attention with…

Messier 46 // NGC 2437: open cluster in Puppis; mag=6.1, size=20.0’, SBr=12.3 mag/arcmin^2, sub-class=III2m

Here we make a beeline to another object from the Messier list, and as with M13, it is the distraction rather than the primary target. Floating as a foreground object amongst the stars of the cluster’s northern section the planetary nebula NGC 2438 can be challenging initially. This is the case because myriad stars of the cluster dot the field of view and our focus is automatically drawn to them. M46 is one of my personal favorite open clusters, being rich and beautiful through the eyepiece. But one must divert their attention away from its beauty to ferret out the planetary.

I have observed this ghostly orb from both my typical suburban backyard with a 5 inch refractor where initially I could not detect it until I popped in an O-III filter. Once I had pinpointed its location and removed the filter, then I could located it despite the distracting backdrop of cluster stars. At our dark site in the 17.5 inch it was a glorious sight. I found it very easy to pick up without a filter, as a somewhat large (for a PNe) grayish-white orb displaying clearly its annular structure.

NGC 2438 and M46_POSS1.jpg

NGC 1924: barred spiral galaxy in Orion; mag=12.5, size=1.6’x1.2’, SBr=12.9 mag/arcmin^2

…vying for your attention with…

Messier 42 // NGC 1976: emission nebula complex in Orion; mag=4.0, size=1.5°x1.0°, SBr=13.1 mag/arcmin^2

When one looks at or thinks of Orion, a galaxy is typically the last thing that comes to mind. Rightfully so as there so many nebulae and open clusters in the constellation that one can keep busy for a long time without even considering galaxies. Of course what does come to mind is the Great Orion Nebula, Messier 42. That is what people really go to Orion for anyway. However, the brightest galaxy within Orion is found less than 2° west of this perennial favorite, yet softly glows in almost total anonymity. Granted it is hardly an attention getter at magnitude 12.5, but still, if you have the aperture and skies to support it, try and give it a little love some time.

I have observed this small puff of light from our dark site, using both a 10 inch and 17.5 inch dobsonian. In the smaller scope it was a somewhat dim small oval that appeared homogenous to the eye. The larger scope certainly helped out quite a bit. The oval remained small but was pretty bright and even displayed some unevenness or mottling across its envelope. While it will not impress, you will at least have the distinction and satisfaction of being able to say you’ve observed a galaxy in a constellation that is rarely if ever thought about when discussing those objects.

NGC 1924 and M42_POSS1.jpg

NGC 6453: globular cluster in Scorpius; mag=10.2, size=7.6, SBr=14.3 mag/arcmin^2, class=IV

…vying for your attention with…

Messier 7 // NGC 6475: open cluster in Scorpius; mag=3.3, size=1.3°, SBr=12.4 mag/arcmin^2, sub-class= II2r

If there is an object that truly flies under the radar, it is this globular cluster. However, that is quite understandable as it sits at the outskirts of a very showy open cluster which is the most southern of the Messier objects. As a young boy the duo of M6 and M7 was one of my absolute favorite objects to observe on warm summer nights with my rickety old Gilbert 3 inch reflector. Little did I know about or likely could have seen anyway, was this dim globular. Found only about 1kpc from the galactic center it suffers heavy extinction from intervening dust. Combine that with the fact it is a background object to M7 in a blindingly rich stellar field, this cluster is indeed challenging.

I have two experiences with this cluster, both of which came from locations farther south than where I live at just over 38°N. From a semi-dark location at around 18°N using my 5 inch refractor I found it a small but distinctly visible round glow at the western edge of M7. However, had I not been looking for it specifically it could have easily been dismissed as a simple concentration in an already very rich field. Then from a location just south of the equator where Scorpius rises quite high, with my 80mm refractor it was nothing more than a fleeting suspicion in the eyepiece. With more aperture and a darker clean southern horizon it should be accessible to many observers. However, the first step is to be aware of its presence.

NGC 6453 and M7_POSS1.jpg

IC 1296: barred spiral galaxy in Lyra; mag=14.0, size=1.1’x0.8’, SBr=13.6 mag/arcmin^2

…vying for your attention with…

Messier 57 // NGC 6720: planetary nebula in Lyra; mag=8.8, size=3.0’x2.4’, SBr=10.7 mag/arcmin^2

Our final DSO pairing is a challenging one. Everyone knows M57 because of its reputation as one of the finest, if not the finest, planetary nebula in the sky. But how many really notice the dim and small galaxy about 4’ to its northwest? It is not an easy target by any means, and your chances are increased by having larger aperture and more importantly darker skies. Not only is its visual magnitude at a weak 14.0, but its surface brightness is also low at 13.6. A mag 11.1 field star less than 2’ to the southwest of the galaxy can also flag its location in the field. But if you have the aperture and conditions, give it a shot. You just might surprise yourself by picking up this dim wisp of light.

My only experience with this little puff of mist is at our dark site with the 17.5 inch. Right before the moon rose above the eastern horizon I was able to snag this one in the steadily brightening sky. It was not a strong presence in the field, even at 296x when it was first suspected. It took me pushing to 422x to confirm this observation. However, on nights when the moon’s influence is totally absent and with even average transparency, I suspect it would have been noticeably easier.

IC 1296 and M57_POSS1.jpg

So there you have it. I hope these curious combinations pique your interest and you give a few of them of them a try. As mentioned some may be too far south, or may not be within reach of your aperture and/or sky quality. But, there should be something here for most everyone to supplement their nightly sky crawls. Adding a little unusual twist can increase the fun of an observing session, and give us pause to consider that there is more out there than what is most obvious to the eye. Good luck in your observing and I hope to see some of these appear in observing reports here on TSS. Keep looking up friends!

Endnote: This article has made use of the MAPS Catalog of POSS I supported by the University of Minnesota. The APS databases can be accessed at http://aps.umn.edu/.)

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