Draco
The Dragon of the North


represents not one serpent of myth, but several. The legend of Marduk is repeated in many cultures with similar tales of dragon slayers. Perseus, Hercules, Cadmus, Siegfried, Beowulf and St. George are all examples. Among these stories are the oldest of all, for some were first told when Thuban was the Star of the North—the Pole Star—some 4000 years ago.
Chaldea was an area along the Euphrates River in what is now Iraq; and the Chaldeans were among the first astronomers. Their dragon Tiamat was a sea serpent who existed even before the sea and the sky had separated from a chaos at the beginning of the world. She was a monster of primeval darkness, who had to be overcome by the powers of sunlight before creation could take place. As time progressed the first gods ascended from the primordial sea and entered into conflict with the force from which they sprang, the evil leviathan Tiamet. But Tiamet rose to the challenge and created evil creatures with poisonous fangs or scorpion stings to help her in the fight. The gods took fright and retreated to safe havens in the sky, with no one—mortal or divine—brave enough to stand against the horde.

At last, however, Marduk of Babylon accepted the challenge and was sent as a champion. At a council of war each of the gods bestowed on him magic powers, and he was sent down to face the ocean monster in battle. But even he trembled and nearly lost heart at the sight of his enemy. He commanded the winds of heaven to blow before him into the face of the foe. As Tiamet opened her mouth in surprise, the winds tore open her jaws with hurricane force and the beast was split asunder. Marduk finished the job with a great club and chased away the army to their place in chaos, since they had no power without the direction of their evil mother.

The north wind carried away the dragon’s blood, and Marduk tore Tiamet’s skin into two pieces. These he used to divide the chaos, and he established heaven and earth. He set aside a home for the gods and created the constellations. He devised the zodiac and the paths of the stars in the sky in a way that they would mark the days, seasons and years. Then he rested from his labors and accepted the praise of both gods and men as the dragon slayer.

Draco is a circumpolar constellation which reaches more than halfway around the pole from a right ascension of 9h30m to 20h40m; it varies in declination from 48 degrees north to 86 degrees—a large area indeed. It wraps around Ursa Minor and also borders Camelopardalis, Cepheus, Cygnus, Lyra, Hercules, Boötes, and Ursa Major. Of 130 naked-eye stars according to the 19th-century German astronomer Argelander, there are only 18 stars through magnitude 4.9, the brightest being Eltanin (from the Arabic for dragon), a double star with components of magnitudes 2.4 and 13.2. Rastaban, Beta Draconis, and Eltanin were considered by the ancients to be the dragon's eyes.

The best known star in Draco is Thuban. About 2800 bc this star was likely much brighter than it now appears, for not only was it the Pole Star, less than ten minutes from the exact pole, but it was designated Alpha Draconis, presumedly the brightest star then in the constellation. This was the time when the pyramids of Egypt were being built. Although there is some doubt, some claim that a descending corridor leading into the depth of the Great Pyramid of Pharaoh Khufu was aligned so that Thuban would be visible, even in daylight, by sighting along the shaft.

By precession of the equinoxes, Thuban will once again become the North Star, but this will not be until about the year 23000, as it takes just under 26000 years for a complete revolution of the Earth's wobble. In the meantime, Polaris will draw even nearer to the actual pole until 2102, but will then give way to Alrai (Gamma Cephei) by the year 4000; after that, Vega stands to inherit the title about 15000 ad.

Draco has a number of double stars that merit your attention. Nu Draconis is a pair of pretty, pale-yellow stars of equal magnitude 5.0, for example.
Draco is the location of the radiant of the Draconid meteors; it serves as the radiant for the Quadrantids of January, too, and for the lesser Eta Draconid shower of late March.


This is a CCD image of the planetary nebula NGC6543 in Draco, taken September 1, 1998, from outside Chabot Observatory. Conrad Jung used his 6-inch Maksutov telescope; the exposure was 40 seconds. Judged to be one of the best planetary nebulae in the sky, at low magnification it looks like an egg.

 



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