Fall Stargazing

In our autumn sky, Perseus can be found towering protectively over Andromeda. His stars form what looks to some like a badly bent boat anchor. From these, the ancient Greeks imagined a battle-clad warrior holding a sword in one hand and the awful head of Medusa in the other. An interesting star in this head is Algol, which means "demon." This star, marking the winking eye of Medusa, varies in brightness every three days. These variations can be easily observed with the naked eye. Another interesting sight visible to a keen eye on a clear night is the "Double Cluster" of stars near the pointed top of Perseus's helmet. The Double Cluster is a wondrous sight through binoculars and telescopes.

Cetus the Sea Monster (sometimes depicted as a whale) also belongs to the autumn sky, and can be found looming to the south of the Great Square. Its brightest star, Diphda, rides so low in the sky that it may be blocked from view by trees or other obstructions. Even more interesting is the star Mira, which means "wonderful." Sometimes Mira will shine about as brightly as Polaris, the North Star, and sometimes it's nowhere to be found. It takes Mira more than a year to complete one full cycle, from bright to dim and back to bright again. Mira and Algol are two examples of what astronomers call variable stars.

Along the Ecliptic
Skimming autumn's southern horizon is Fomalhaut, the brightest star in the otherwise-obscure constellation of Piscis Austrinus, the Southern Fish. Above Fomalhaut are many dim stars that the ancient Greeks assigned to Aquarius the Water Bearer, the figure of a man carrying a large jar on his back. The ecliptic, the path that the Sun appears to follow in the sky, also passes through Aquarius. Not to be confused with the Southern Fish, Pisces the Fishes is another constellation along the ecliptic that is composed of very faint stars. The constellation is usually drawn as two fishes, one to the south of the Great Square, another to its east, and joined at the tails by a long rope.

East of Pisces along the ecliptic lies the small constellation of Aries the Ram. It contains only one bright star—Hamal—which combines with two fainter suns to form the head of the animal. Aries was the legendary Ram of the Golden Fleece, which was pursued by Jason and the Argonauts.

Autumn is a season of change, both here on Earth as well as up in the sky. Enjoy the relatively warm nights now, for the cold, crisp nights of winter are just around the corner.

Fall Color and Constellations
Native Americans had an interesting tale to explain why leaves turn red and orange at this time of year, which involved the constellation of Ursa Major, the Great Bear. Every spring, a particularly ferocious bear left its den to wreak havoc on tribes throughout the land. To help rid them of this menace, the chiefs decided to send their three mightiest warriors after the bear. The warriors chased the bear across the sky throughout the summer. Finally, in the autumn, as the bear tired, one of the hunters wounded it with an arrow. Blood dripped from the wound and colored the leaves of the forest. But don't worry, the bear is fine. Both it and the relentless hunters return to the sky every spring.