Hobbies And Interests
Single Stars
More than 76 noticeably bright stars have been identified in Draco, with Eltanin being the brightest. The brightest star of a constellation is called the "alpha" star; however, in this constellation the Alpha Draconis title was given to Thuban. On a descending list of magnitude, Thuban rates fairly low compared to its companions, but it appears brighter because of its position in an atmospheric arc that causes a refraction making it appear closer and thus brighter. Thuban was the North Star until around 2700 B.C., before the Earth's axis shifted, positioning Polaris in this key location. As the Earth continues to "wobble," Thuban is expected re-gain its position as the North Star in the year 21,000.
Binary and Variable Stars
In addition to single stars, Draco has dozens of binary stars, which are a distinct pair of stars. When positioned just right, the light of emitted from a pair may cause the stars to appear quite bright, while stars in other pairs may eclipse the light of its partner. Some pairs and single stars are variable stars that have inconsistent brightness levels. This variability of brightness occurs at the beginning and end of the star's life and includes novas and supernovas. Most stars can be seen through binoculars or the naked eye when conditions are right.
Planetary Systems
By sending telescopes deep into space, scientists have located planetary systems in the Draco constellation. As of May 2011, 10 systems have been located, each with one orbiting planet. Most of the stars are cooler than the Earth's sun, however Kepler-10 and HD 109246 are sun-like stars. HAT-P-7 appears similar in temperature to the sun, and is the farthest away at 1,040 light-years. The closest planetary system is Iota Draconis, only 100 light-years from Earth.
Deep Space Objects
Draco includes a 3-D extension through the Milky Way to end of space to include a wide variety of deep space objects such as galaxies, nebulae, planetary nebula and quasars. Many individuals have taken photos of Draco's deep space objects, including Californian pilot Glen Youman, who maintains an extensive archive of images at Astrophotos.net. As of April 2011, Youman has captured 35 of Draco's galaxies of varying traits, including three that are 283 million light-years away. Among his collection, there are two sets of "galaxy pairs," one of which has interacting galaxies.
Missing Messier Object
French astronomer Charles Messier originally found one of Draco's galaxies, which he noted in the Messier catalog as M102. As others attempted to find Messier's 110 objects, M102 was thought to actually be M101, with Messier mistakenly noting it twice. This error lead to a "missing object." The confusion was probably due to this galaxy being faint and edge-on, appearing more like a bulging line. M102 is called a lenticular galaxy because it has no arms spiraling outward from the central bulge. The galaxy is classified as NGC 5866 from Johann Dreyer's "New General Catalogue" published in 1888.
Cat's Eye Nebula
The Cat's Eye Nebula was discovered by William Herschel in 1786. Cataloged as NGC 6543, the Cat's Eye Nebula is situated in the direction of the North Ecliptic Pole, about 3,000 light-years from Earth. The Goddard Space Flight Center notes this complex nebula is a 1,000-year-old "visual 'fossil record' of the dynamics" of a dying star. Photos from the Hubble telescope suggest it was once a double-star system, which explains several "curlicue" features and bright arcs near the outer edge of the gas lobes.