Map 3: North Polar 3
Draco to Cassiopeia
August 1, 2007
Cepheus the King and part of the huge constellation Draco the Dragon make up most of Map 3. This area of sky may not contain many bright stars, but it offers a variety of celestial targets, from red stars to galaxies.
Start your deep-sky hunt 5° southeast of Zeta Draconis with the Cat's Eye Nebula (NGC 6543). Depending on your color perception, you'll either see this planetary nebula as greenish-blue or bluish-green, but you will see color. Through a 10-inch scope, the Cat's Eye resembles a somewhat unstructured spiral galaxy. An outer shell of gas 5' across surrounds the "eye," but seeing this feature requires a 16-inch or larger telescope.
Only 1¾° northeast of Omega Draconis lies NGC 6503, a 10th-magnitude spiral galaxy that even a 4-inch scope will reveal. NGC 6503 is roughly 3 times as long as it is wide. Its central region appears elongated, and the brightest part is not exactly centered.
In Cepheus, you'll find open cluster NGC 6939 easily. It forms an equilateral triangle with 3rd-magnitude Eta and 4th-magnitude Theta Cephei. NGC 6939 is an 8th-magnitude group of roughly 60 stars between magnitudes 11 and 13 in an area 5' across.
Along Cepheus' southern edge lies Herschel's Garnet Star (Mu Cephei). Astronomer William Herschel first described it in the 18th century. Glowing at 4th magnitude, Mu is one of the sky's reddest stars — a sure cure for the observing blues.
Mu marks the northern edge of emission nebula IC 1396. This giant object spans 2° (4 Full Moons) and is difficult to see in 6-inch or smaller telescopes. In larger instruments, IC 1396 appears as a circular mist crossed by many dark lanes.
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