Sky Watch: A dolphin's constellation

Whenever I'm out under a dark summertime sky sharing the stars with the public, I always try to point out the most beautiful and historic constellations. It's amazing howI'm always surprised to learn that one of the crowd's favorite constellations is not the brightest or the largest but rather one of the faintest and smallest of all; it always elicits gasps of excitement in those who spot it for the first time.

After sunset at this time of year, go out and gaze midway up into the eastern sky, and you'll see its three stars shining brightly there.

At the westernmost vertex of the large triangle lies the brightest of the trio: Vega, the most prominent star in the constellation of Lyra, the harp. The lower right-hand star of the triangle is Altair, which marks the constellation of Aquila, the eagle. Completing the figure is Deneb, the faintest of the three stars, forming the tail of Cygnus, the swan.

And, if you have a really dark sky, you'll easily see the bright star clouds and dark rifts of the Milky Way flowing south to north through the great triangle.Once you find this celestial marker, you should be able to locate Delphinus, just below, and see the tiny outline of a dolphin leaping from the water toward the north.

The Hindus knew this star grouping as a porpoise, the Arabians as a riding camel, and in early Hebrew tradition, it was sometimes identified with the Great Fish of Jonah. Its four main stars form a grouping that some call "Job's Coffin," though the origin of this name seems lost in history.Its two main stars, Sualocin and Rotanev, were first mentioned in 1814 in a star catalog published at the Palermo Observatory in Italy. Read backwards, these two words form the name "Nicolaus Venator," which is the Latin version for the Italian name Niccolo Cacciatore, who, at the time, was the assistant director of the observatory.

According to one legend, Delphinus is the dolphin that carried the Greek poet Arion safely to shore at Tarentum, allowing him to escape his enemies. The figure of a youth on the dolphin appears on a classic series of silver coins issued at Tarentum in southern Italy around 370 B.C. The dolphin also appeared prominently on the splendid coins of Syracuse in Sicily, dating from about the fifth century B.C. In fact, the silver coins designed to commemorate the great victory over the Athenians in 413 B.C. have been considered by some to be the most beautiful of all time.

Find the dolphin in the sky, and you'll see why it's been the object of so much admiration through the ages.