How to Find the Draco Constellation

How to Find the Draco Constellation Draco is a long, winding constellation easily visible to northern hemisphere observers. Its one of those star patterns that actually does look somewhat like its name, tracing out the long body of an exotic dragon across the sky.   Finding Draco Constellation Locating Draco is pretty easy in clear, dark skies. The best way is to first locate the north star Polaris, or look for the Big Dipper or the Little Dipper. They are on either side of the long body of the celestial dragon. Its head is at one end, near the constellation Hercules and its tail is up near the bowl of the Big Dipper.   This chart shows Draco in relation to nearby constellations of Ursa MInor (the Little Dipper) and Hercules. Click to enlarge. Carolyn Collins Petersen Draco Constellation Mythology The ancient Greeks envisioned Draco as a serpent-dragon, which they called Ladon. They placed it close in the sky to the figure of Hercules. He was their mythical hero who, among many other notable actions, killed the dragon as one of his twelve labors.  Over the centuries, the Greeks spoke of Draco going after heroines, particularly the goddess Minerva, as well as his adventures as the son of the Titan Gaia. In contrast, the ancient Arabic astronomers saw this region of the sky as home to two hyenas attacking an infant camel who is part of a mother group of older camels. The Stars of Draco Constellation Draco has fourteen brighter stars that make up the body of the dragon, and many others that lie inside the official IAU-designated region for the constellation. Its brightest star is called Thuban, which was our north star at the time the ancient Egyptians were building their pyramids. In fact, the Egyptians angled certain passageways inside the pyramids to point directly at Thuban. Thuban existed in a region of the sky that they believed was a gateway to the afterlife.  Therefore, if the passageway pointed there, the soul of the pharaoh would have a direct pathway to his reward. The official IAU chart showing the region of the northern hemisphere sky that contains constellation Draco. IAU/Sky Publishing. Eventually, due to the procession of Earth on its axis, Thubans position in the sky changed. Today, Polaris is our north star, but Thuban will be the pole star again in about 21,000 years. Its name is derived from the Arabic term that means snake. This chart shows how Earths north pole precesses as Earth wobbles on its axis. The result is that the pole appears to point at different stars over the course of 26,000 years. Right now it points at Polaris, but in the past (and in the future) Thuban is a target. Based on a graphic provided by Tauolunga, via Wikimedia Commons Attribution Share-Alike 3.0 license.   Thuban, also called ÃŽ ± Draconis, is a binary star system. The bright one we see is accompanied by a very faint star that orbits very close to its partner. The second-brightest star in Draco is called ÃŽ ² Draconis, with a familiar name of Rastaban. It is near the bright star ÃŽ ³ Draconis, which is also called Eltanin. Interestingly, Eltanin is actually the brightest star in Draco.   Deep-Sky Objects in Constellation Draco This region of the sky has a number of faint deep-sky objects that require binoculars or a telescope to see. One of the most famous is the Cats-Eye Nebula, also known as NGC 6543. Its a planetary nebula that lies about 3,000 light-years away from us and is the remains of a sun-like star that experienced its final death throes some 1,200 years ago. Before that, it gently blew off its material in a series of pulsations that formed concentric rings around the dying star.   The Cats Eye planetary nebula, as seen by Hubble Space Telescope. NASA/ESA/STScI The unusual shape of the nebula is due to the clouds of material blown away from the star by a fast stellar wind. It collides with material that was ejected earlier in the stars aging process. The cloud of material is mostly hydrogen and helium, mixed with other materials. Astronomers suspect there may have been a binary companion star involved, and interactions with it may have caused the complex structure we see in the nebula.   Viewing the Cats-Eye Nebula requires a good small- to medium-sized telescope, since its actually quite dim. The nebula was discovered by William Herschel in 1786 and has been observed by many professional astronomers using both ground-based instruments, the Hubble Space Telescope and the Chandra X-ray Observatory.   Observers with good telescopes can also spot several galaxies in Draco, as well as galaxy clusters and colliding galaxies. Its well worth a few evenings of exploration to ramble through Draco and spot these fascinating objects.