I have spent many happy hours observing in the constellation Lyra, first in July 1971 when I observed it over two nights from northern Ontario with my Tasco 4.5" Lunagrosso reflector! I thought I had hit the jackpot when I found M 57, and again later with M 56, using those crappy .96 Kellner and Huygens eyepieces.
I returned with my Edmund 8" reflector in July 1978, also from a dark sky site in northern Ontario. With such a big aperture and much better eyepieces, I enjoyed unrivaled views of both Messier objects, even resolving the outer edges of M 56 at higher powers.
In 1992, equipped with better books and maps, I once more found myself immersed in a study of Lyra, again with my trusty 8" reflector. I was able to add two new NGC objects, the very challenging oc 6791, which the 8" managed to partially resolve at high power, and eg 6703, seen from my suburban backyard in Essex County, Ontario. I was able to view the galaxy at up to 200x!
Now comes July 2013. Light pollution marches on. Though I have doubtless observed the Ring Nebula many times since 1992, this marked my first official visit to Lyra in 21 years! Equipped with the Uranometria Atlas, all sky edition, and a 12" reflector, this was a very different adventure. There are a total of 29 NGC objects brighter than mag. 15 plotted on the atlas, along with 3 IC objects and one "other," an open cluster labeled Ste 1. I also went after a few new closer and fainter double stars, and reviewed a number of old favourites. However, this blog will only deal with the NGC and similar objects.
Here is a breakdown of the NGC objects. 24 of them are galaxies, many of them very faint. However, a small number of them are easily viewed in a 12" mirror, and should be better known by experienced viewers. 2 of the NGC located in Lyra are open clusters, including one that my object locator says does not exist (it does!). There are two planetary nebulae, giving the famous Ring Nebula some company. There is a single globular, an often overlooked showpiece (M 56). The 3 IC objects are all galaxies. For a mid-summer Milky Way constellation, Lyra has no less than 27 NGC-IC galaxies! I was anxious and excited to locate them. I only struck out on two, having success with the other 25! I will continue for a few more sessions to try and locate the missing pair. Details below.
In this first of two blogs concerning deep sky objects in Lyra, I will discuss the non-galaxy objects. In Part 2 I will tackle the galaxies.
pn 6720--M 57: This could possibly be the most famous Messier object of them all, and perhaps the most famous deep sky object of them all, too. It is likely one of the most photographed NGC objects. Since first seeing it with the 4.5" Tasco reflector, I have had a deep love for it. It is stately, grand, strangely silent (it seems as if it should be accompanied by a low hum, or something similar), awe-inspiring and impressive in nearly any telescope. Last night I observed it up to 300x in the 12", noting feathery texture on its huge surface. I also had an opportunity to view it in a 4 1/4" Edmund Astroscan RFT reflector, at a much lower magnification. It was tiny and certainly dimmer, but still majestic and impressive, especially with an ultrablock filter. If a viewer is not impressed with M 57, then he is probably in the wrong hobby!
http://schickworld.com/Astronomy/Resized/M57-LRGBv2011S.jpg
pn 6765: Located an easy star hop from M 56, Lyra's "other" planetary nebula is worth a look, at least with a 12" scope or larger on a dark night. Located at 100x (15 mm eyepiece), at 67" and mag. 12.9 it is about 1/3 the size of M 57, though significantly dimmer. At 125x (12mm) I used an ultrablock filter, getting good direct views. Expecting a round or oval object, I was surprised to observe a slash, like an elliptical galaxy. At times I thought I saw a central star, but this observation could not be repeated on subsequent evenings. Located within a triangle of brighter stars (mag. 10-11), it was observed up to 200x, with better views using the filter. The shape now reminded me of the body of an Astroscan telescope, being in two parts joined together, one of them round and larger, and the other much narrower, like a short neck protruding. Is this a double planetary? A puzzling but fun object to observe, and no doubt somewhat overlooked.
http://www.ngcicproject.org/dss/n/6/n6765.jpg
There are 3 open clusters in Lyra, 2 from the NGC, and one from Stephenson. I will begin with the newest cluster.
oc Ste 1: According to the newest edition of Uranometria, the area around Delta 1 and Delta 2 is now a very large and bright open cluster. With a size of 40', use a low power eyepiece. I loved the view with my 25 mm, giving 60x. A dozen stars appear to be contained in a box by four brighter stars (Delta 1 is a deep, rich golden yellow), and another dozen lie outside the box. I also viewed this at low power with the Astroscan 4 1/4", enjoying the views a lot. The cluster is suitable for all apertures, even very small refractors.
oc 6791: One of the best open clusters out there for larger scopes, so use at least an 8" mirror for this one. Even the 12" does not fully resolve it, at least in my best sky. First viewed in 1992 with the 8" scope, it took 150x back then to even begin to resolve it. I can't wait to see this in my friend's 22" Dob! At low power (and 12"), a large, hazy cloud of dim whiteness can be seen. Official size varies between 10' and 20', depending on which information source is used. I tend to go for the 20'. There is certainly a very dense core to this cluster, but the haze spreads out beyond the main section. At 125x it begins to resolve, and even more so at 150x. Take your time and let your eye do its work, and very faint stars will pop out all across the object. Think of it more like a tough globular and you will get a better idea of how to respond to it. At 200x I enjoyed remarkable views, though there was still some haze back in there. I observed it this year over many nights, and the cluster is a good indicator of how suitable the sky is that night for deep sky observing. It is more difficult to resolve than many globulars, so be patient and wait for your best night.
http://www.ngcicproject.org/dss/n/6/n6791.jpg
oc 6743: Perhaps justifiably overlooked, nonetheless these are the objects I often enjoy tackling, for that very reason. When I keyed in 6743 on my object locator keypad, I was informed it was non-existent. Good thing Uranometria knows more than my keypad! Though hardly a traditional cluster, and certainly not something you would proudly show your grandmother, the little group fits a familiar pattern for observing pros. A bright star (mag 8) sits right in the middle of a very faint star cluster, dimming its members and hiding some, too. Best at 150x, I counted 18 very faint stars surrounding the bright one. I also used the cluster to star-hop to a nearby faint galaxy (eg 6740).
http://www.ngcicproject.org/dss/n/6/n6743.jpg
gc 6779--M 56: The final non-galaxy deep sky object in Lyra is the 2nd finest object in the constellation (oc 6791 is 3rd). Unresolvable in a 4", the 8" used to do a pretty good job with the outliers, but not so well with stars in the core. This is a showpiece object, often overlooked by amateurs in favour of M 13 and other more popular globular clusters. My 12" mirror gives a remarkable view, aided by an adjacent bright star that allows perfect focusing. Up to 200x the cluster is still bright, and resolving all across the center, which breaks into uneven segments of stars and haze, with dark lanes separating them (the 8" showed some of this, too). I found it harder to focus at 250x, though the object was still good at this range for an experienced eye. It is a very compact group, but its overhead sky position gives it a huge advantage over brighter and larger globulars further south on the horizon.
http://www.ngcicproject.org/dss/n/6/n6779.jpg
This concludes Part One of my deep sky look at Lyra. In the next entry, I will discuss the constellation's 27 galaxies! Stay tuned, and come back often.
Mapman Mike
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