Draco Draco, the Dragon, is a northern constellation that is circumpolar for observers north of 40 degrees north latitude. Hold your mouse cursor over the image to see constellation figures, boundaries, and star identifications. The name Draco is representative of several different dragons in Greek and Roman mythology. In the Greek version, Draco represented the dragon Ladon, which guarded the Garden of the Hesperides. This was the orchard of the goddess Hera where she grew golden apples that gave immortality. Hercules, immortalized in a nearby constellation, killed Ladon to get the golden apples. Alpha Draconis is Thuban. It a shines at magnitude 3.65. It is a giant of spectral class AO. It is located 303 light-years away. In Arabic, Thuban means the "Snake." Thuban holds an important place in sky lore because it was the pole star from 3942 to 1793 B.C.E. (Before the Common Era). Because of precession, the wobble of the Earth's axis, the location of the celestial poles change over a time period of 26,000 years. Thuban was the pole star when the Egyptians were building the pyramids around 2,600 B.C.E. Now the north celestial pole is located close to Polaris, Alpha Ursae Minoris. Draco was an important constellation in ancient cultures because it guarded the north celestial pole, which was believed to be a passageway between the mortal world on Earth and the immortal world in heaven in the sky. The brightest star in Draco is Gamma Draconis. Its popular name is Eltanin, which is also spelled Eltamin. It shines at magnitude 2.36 and is located at a distance of 154 light-years. It is a spectral class K5 red-giant star. Draco contains only one Messier object: galaxy M102. But it does contain several other fascinating deep-sky objects, such as NGC 6543, the Cat's Eye planetary nebula, the Draco Trio of galaxies (NGC 5985, NGC 5982 and NGC 5981), NGC 5907, the Splinter Galaxy, and Arp 188, the Tadpole Galaxy. Draco was cataloged by the Greek astronomer Ptolemy in the second century C.E. (Common Era). It is the eighth largest of today's 88 modern constellations, covering 1,083 square degrees of sky. Ursa Minor Ursa Minor, the Lesser Bear, is a circumpolar constellation for observers north of 20 degrees north latitude. The constellation figure of Ursa Minor is basically the same as the Little Dipper. Its shape can be hard to pick out at a light-polluted observing location because its stars are faint, except for Polaris and Kochab, which are only second magnitude. Alpha Ursae Minoris is Polaris, the pole star. This second-magnitude supergiant star is currently 0.75 degrees from the north celestial pole. It is a spectral-class F type star that is also a double star with an 8.8 magnitude companion that is 18 arcseconds away. Polaris is located 430 light-years distant. Polaris is also a Cepheid variable star that varies 0.03 magnitudes in brightness over a 3.97 day period. Beta Ursae Minoris is Kochab, a magnitude 2 spectral-class K type star that is similar in brightness to Polaris. It is located 126 light-years away from the Earth. Ursa Minor was cataloged by the Greek astronomer Ptolemy in the second century C.E. (Common Era). It is the 56th largest of today's 88 modern constellations, covering 256 square degrees of sky.
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