International Star Registry

All Constellations

Hydra - Sea Serpent

A water serpent, probably so named because it wanders just about everywhere in a space of more than 100 degrees in length. It lies south of Cancer, Leo and Virgo, and reaches almost from Canis Minor to Libra.

Hydra has only one significant star. Then known as “Alphard” or “the solitary one”, it is the heart of the sea snake. It is an orange 2 magnitude star just below the configuration of the snake’s nose and head. Hydra is best viewed from February to May.

The astrologers of the east, in dividing the celestial unknown into various compartments, assigned a popular and allegorical meaning to each. Thus the sign Leo, which passes the meridian about midnight when the sun is in Pisces, was called the House of the Lions, Leo being the domicile of Sol.

Of the two serpents among the constellations, the polar one represented the oblique course of the stars, while the Hydra (Great Snake) in the southern hemisphere symbolized the moon’s course. The Nodes are called the Dragon’s head and tail to this day.

The Lernean hydra was a terrible monster infesting the neighborhood of Lake Lerna in the Peloponnesus. Diodorus, the first century B.C. historian who supposedly knew about such things, claimed that it had a hundred heads. Simonides (600 B.C.) said it had 50. The more commonly agreed-upon opinion said it had nine. At any rate, as soon as one head was cut off, two immediately grew up if the wound wasn’t cauterized by fire. So the stories were bound to differ depending on how many sword slices and how many fires there may have been before any witnesses got to the scene.

Destroying this cute little monster was one of Hercules’ labors. Iolaus, his nephew, lent a hand by applying a burning iron to the wounds as soon as Hercules cut one of the heads off. While this was going on, Juno, jealous of the glory Hercules was accumulating, sent a sea-crab to bite off his foot. Hercules did in the sea-crab as well (no big deal after a few hydra heads), thwarting Juno’s attempts to lessen his fame.

This fable of the many-headed hydra may represent nothing more than the fact that the marshes of Lerna were infested with a multitude of serpents, which seemed to multiply as fast as they were destroyed. The story of the Hydra lends more drama to the myth of Hercules.
Right Ascension 10:18
Diameter (°)56
Area (square °)1303
Opposition Feb 21
Size Rank 1st
Brightness Rank 24th