Now in view over in the southeast at around 9 p.m. local daylight time, is the dim constellation of the Sea Goat. Incidentally, it should be emphasized to newcomers of astronomy that the currently accepted name of this constellation is Capricornus, and not Capricorn.
Capricornus in Latin means literally “horned goat.” You might have heard of the famous island of Capri in Italy: its name means “the island of goats.” But in the old star atlases, Capricornus is depicted by the figure of a sea-goat, combining the forequarters and head of a goat and the tail of a fish.
The Stars of Capricornus
Principally astrologers (and some older astronomy books) use the latter for labeling the zodiacal sign of that name. But quite frankly, if the Sea Goat were not in the zodiac most people probably would not even know its name. Its stars—Algiedi and Dabih—form a roughly triangular figure which somewhat suggests an inverted cocked hat.
The star Algiedi, is really a pair of stars so widely separated that they can be easily distinguished without any optical aid. Below Algiedi is the star Dabih, also a pair, though binoculars are needed to see the seventh-magnitude companion of the brighter star.
The lore behind Capricornus is rather amusing. Apparently, the god Pan was involved in a wild picnic-party with the other gods when a huge, ferocious monster called Typhon suddenly appeared. To escape him, each god changed himself into an animal and fled. However, in Pan’s alarm (hence the word “panic”), he jumped into a nearby river before completing his transformation into a goat. As a result, his lower extremities assumed the form of a fish!
To find Capricornus, locate the asterism, the Summer Triangle, then draw an imaginary line from Vega and through Altair to locate this constellation low in the southern sky.
Joe Rao is an esteemed astronomer who writes for Space.com, Sky & Telescope, and Natural History Magazine. Mr. Rao is a regular contributor to the Farmers' Almanac and serves as an associate lecturer for the Hayden Planetarium in New York City.