Image generated with Starry Night Pro 6.
"The muse is upon me… bring me a small lyre!" – Caesar (via Dom DeLuise)
I have come to the conclusion that the constellation Lyra is my favorite, as it has all of the qualities one looks for in a celestial marker for a student of astronomy history, an amateur astronomer, and a part-time musician (well, drummer). Within its defined borders reside a famed double-double star system, a planetary nebula, a small globular cluster, at least one reasonable galaxy, one of the brightest stars in our night sky, a near-perfect parallelogram (if these were brighter stars, they would rival the Belt of Orion in geometric significance to terrestrial observers), one corner of the largest asterism in the night sky (the so-named Summer Triangle), and a host of other stars and dimmer objects (including even a few comets right now). This great variety of objects all lie in a small piece of property just off the band of the Milky Way and, during the summer, they are all ideally suited to near-zenith or at-zenith observing.
For our overture, we begin with the history of this mythic instrument. Lyra has most oft been associated with the famed musician of olde Orpheus, where Orpheus' lyre was disposed of in a river not long after Orpheus himself was disposed of by maenads despite Orpheus giving the performance of his life (or for his life as the case may have been, as his playing reportedly kept rocks and ï¿¼sticks at distance, requiring the maenads to forego accouterments and pluck Orpheus apart with their own hands). Zeus, with his ever-present eye for collector's items, ordered the lyre placed in the heavens along with the eagle that recovered it (and some old drawings of the constellation still include a bird of some kind in the rendering).
The show continues with the frame of the lyre itself, rendered in the opening image as a parallelogram topped by a "T." When I see the constellation, I don't see the "T" as much as I see an additional triangle composed of Vega, a Lyr (a double-star that connects the triangle to the parallelogram), and 1a/2a Lyr (far left of the image above, connected by the red line). Now then, 1a/2a Lyr is a sight to behold in a telescope, as it is not one star, but instead a pair of binaries, meaning four stars total that resolve nicely under reasonable magnification (it is reported that, under ideal conditions, the two pairs themselves can be split naked eye). This famed "double-double" star is shown below in an image from the Harrison Telescopes website.
Vega is the fifth brightest star in the Night Sky (making it the sixth brightest star in our sky) and is the second star to appear during the summer months after Arcturus. During June and July, Vega first appears high in the North-Eastern Sky and is obvious to anyone waiting at Darling Hill for their eyes to adjust after sunset. This makes Vega an easy marker for anyone learning the Summer constellations, which then makes Lyra an easy constellation to get under one's belt at the same time. The parallelogram (where one might imagine the plucked strings of the lyre to be) is oriented nearly North-South and runs along the neck of Cygnus the Swan, a Constellation embedded well into the river of stars that make up the Milky Way.
With the constellation of Lyra identified from its two prominent geometric themes, the search for the subtle tones in this constellation can continue. After M13 in Hercules and the famous M31, the object I learned to identify from the relative positions of stars was M57, the Ring Nebula. M57 sits like a tuning knob at the base of Lyra, almost centrally located between the binary star Sheliak and Sulafat. While far from the brightest object in the night sky, the Ring jumps out immediately even under low-power binoculars as something clearly not a pinpoint of light. New scope owners looking to find anything(!) in their scope are well-advised to consider M57 as a target for low-magnification observing, as the appearance of Sheliak and Sulafat in an eyepiece help to set bright boundary conditions between which to scan for the nebulous ring. On ideally clear and steady nights, the central star of the Ring is visible, although this can be a heroic undertaking for even seasoned pros. A comparison of what Hubble sees and what you'll likely see is provided on the previous page.
Containing the Ring Nebula would be enough for any constellation to be noteworthy to an amateur astronomer, but Lyra is famous as being a host to yet another Messier object in the form of M56, captured above-right by Stu Forster in July of 2010. This small globular cluster has been tagged at 13.7 billion years of age and can be found most easily by drawing a straight line between Sulafat and Alberio (the head of Cygnus the swan) and scanning the midpoint with larger-aperture binoculars or a small telescope.
For those listening most intently to the orchestrations of this constellation, the irregular galaxy NGC 6745 is just visible in medium-sized telescopes (shown above from Hubble). NGC 6745 is decidedly less J. S. Bach and decidedly more John Cage, as 6745 is actually three galaxies in the process of a violent dance. Like a famous Big Band moving through a town of jazz combos, the largest galaxy is pulling stars from the two smaller galaxies, populating itself at the expense of the disrupted musicians.
There are even themes implied but not heard that enhance the complexities of Lyra. To date, over 13 exoplanets have been discovered in Lyra, at least three of which are attributed to the position of the Kepler Mission observing envelop just beyond Cygnus (see the image above, which shows Kepler frames just to the edge of Lyra).
– Happy Hunting, Damian
Image generated with Starry Night Pro 6.
Draco, like all reptiles, is a bit on the dim side. Most of its constituent stars are in the 3 to 4.5 Magnitude range, making it an easy target in dark skies but a bit of a hunt near larger cities. If you've never looked for it before, it rivals Ursa Minor (the Little Dipper) in terms of "meh" apparent brightness in the sky (so it is far less pronounced than the Big Dipper or Cassiopeia, the two most prominent Constellations in this part of the sky).
Your best bet for identifying the stars in Draco may be to start right at the head and work your way down (and around, then over, then up, then way over the other way). One of my recent discoveries is that the head of Draco is, itself, a noted asterism (or noteworthy arrangement of stars that are not of the proper 88 Constellations) referred to as "The Lozenge" ("1" in the image above). I had been subconsciously thinking of Monty Python references to throw into this article and realized that saying "The Lozenge" several in a low John Cleese voice a la "The Larch" just about does it. The head of Draco is made from the brightest stars in the Constellation and does make for a reasonably easy target, as it sits between the two bright stars of the Little Dipper's bowl ("2" In the image at right) and Vega ("3"), the ridiculously bright star making its triumphant return to Spring skies (if you're at Darling Hill near sunset, you will see Vega as one of the first stars to appear above the Eastern Horizon well before it gets really dark). For those of you familiar with the Keystone (another famed asterism) that makes up the torso of Hercules ("4" in the image above), simply drive your eyes to the left-ish during the early night.
The historical origins of Draco as a lizard of any kind are localized to the Mediterranean, and these origins go back far enough that Draco is one of the Almagest's Original 48. The Greeks, and so the Romans, saw Draco as a Dragon (or, at least, lizard) of generally ill repute. Draco was seen by the Greeks as a guard of Hesperides' golden apples and/or a guard (or target, depending on how you read the sentence) of Jason's mythical golden fleece. The Romans saw Draco as the remains of the dragon killed by their goddess Minerva. It is perhaps fitting that, if you imagine Ursa Minor (the Little Dipper) as an ax on a questionably straight handle, then Draco is precariously on the celestial chopping block preparing to be cleft in twain.
The body of Draco is a healthy mix of single and double stars. In the boring single star category are Giausar, Thuban, and Nodus I. The double star list includes Edasich, Aldhibain, Altais, Rastaban ("eh mahn!"), Eltanin, and Grumium.
Thuban is one star in Draco to spend a bit of time on. In fact, it's one to spend several thousand years on. As late as 2700 B.C.E., Thuban held the place of Polaris as our North Star. The Earth may seem reasonably unchanging with respect to the seemingly unchanging arrangement of stars of our 100-year-ish lifetimes, but on the geological or cosmological timescales our Earth is as dynamic and fast-moving as that famed clay dreidel. The 26,000-year cycle we know as the precession of the equinoxes (shown above) is one of those processes that requires nearly the entire history of what we know as civilization to mark significant timespans for, but it is reported in several places that Thuban was of significance to the Egyptians in their building of the pyramids over 5 millennia ago (I would be happy to report that Thuban was the North Star that the main shaft of the great pyramid of Cheops was aligned to, but I've found conflicting reports online from otherwise reputable locations, so will simply report that the Egyptians very likely knew that this star appeared to move far less over the course of the night than any other and, therefore, held it with great regard).
For those observing at Darling Hill or anywhere south of Syracuse, Draco is a tough reptile to sustain one's astronomical appetite on. At least two comets are currently passing through Draco at the moment. One, LINEAR (C/2011 F1), is just off the Spindle Galaxy M102 (we'll come back to that) and, at 3 a.u. and closing, may improve beyond its apparent magnitude of 12.5. Draco also hosts Garradd (C/2008 P1) far beyond its tail star. At an apparent magnitude of 21.30, you have absolutely NO chance of seeing this comet from Darling Hill.
Draco is regrettably light on deep sky objects as well. The local color (at about 3400 light year) is provided by NGC 6543, known as the Cat's Eye Nebula (above). This is regarded as one of the most structurally complex nebulae in the Night Sky, although this complexity is only revealed through astrophotographic studies. NGC 5866 (below), also known as the Spindle Galaxy (which is very likely Messier 102, although some debate exists), is one of the great photographic sights in astronomy to my eyes. This edge-on galaxy view produces amazing density of material and spindly, fibrous clouds of dust and stars along the plane of the galaxy and a bright glow of stars all around this dense, dark line.
Now, the long curving body of Draco and its positions near the North Star does afford it one benefit in the Northern Horizon. Satellites! There are many bright (brighter than magnitude 4.0) satellites that follow paths over the Earth's poles, meaning those Constellations near the North and South poles are constantly getting pierced by manmade weather, communications, and "other" satellites. Simply letting my copy of Starry Night Pro go at high-speed with Draco at the center reveals over a dozen of these satellites over the course of just a few hours.