The most beautiful of all the zodiacal constellations is now visible, low toward the south as darkness falls. This is Scorpius, the Scorpion. And unlike some cryptic sky creatures, the bright stars of this constellation cut a figure that really looks like what its called.
The Scorpion's body is formed by the upper stars of this pattern; its tail slants toward the horizon, then curves to the left and upward, a fine stream of stars ending in a wide pair that marks the creature's stinger. George Lovi (1939-1993), a well known astronomy lecturer and author, used to say that it always bothered him that a striking star pattern such as Scorpius was made to represent "a lowly, creepy-crawly thing that has few friends."
There were mythological reasons, though, for its location. One legend has it representing the creature that stung Orion, the Mighty Hunter, to death. To honor Orion, the Scorpion was placed opposite him in the sky, so that these celestial antagonists will never meet again. Indeed, when Orion is disappearing below the western horizon during spring evenings, the Scorpion is just poking its own head up in the southeast.
able --> Scorpius is a constellation that can be best appreciated by southerners.
Those who live in the far-northern United States, southern Canada or the British Isles will have part or even all of its tail hidden below the southern horizon. As one progresses farther south, the Scorpion slowly climbs the southern sky. Scorpius is directly overhead in Australia, New Zealand, South Africa, northern Argentina, Uruguay, most of Brazil, northern Chile and southern Peru.
The Milky Way passes through the lower extremities of the Scorpion. Here clouds of stars and dark interstellar dust combine in a bewildering array that can be seen in binoculars and telescopes.
The Scorpion's brightest star is the first-magnitude Antares, displaying a reddish hue. To the ancients, this distinctive red color suggested the planet Mars, and the name Antares means literally "The Rival of Ares," Ares being the Greek name for the God of War. To the Romans, the God of War was called Mars.
In the time of Confucius, the Chinese called this star Ta Who, "The Great Fire."
Antares is a cool, red supergiant star, about 604 light-years away. It is 9,000 times more luminous and about 700 times the diameter of our Sun. If our solar system were centered on Antares, the orbit of the Earth would easily fit within this star.
Yet despite these impressive statistics, it should be noted that the overall density of Antares is less than one-millionth that of the Sun. Antares is also relatively cool as stars go, only about 6,500 degrees Fahrenheit (3,600 Celsius), compared to roughly 11,000 degrees F (6000 C) for the Sun. Its low temperature accounts for the star's ruddy color.
Antares has a small, very hot companion, bluish-white in color. The smaller star has also been described appearing as "a little spark of glittering emerald" because of its proximity and contrast to ruddy Antares. The pair orbit each other over a span of nearly 900 years, separated by a distance of about 500 times Earth's distance from the Sun.
Two years ago, the familiar head of Scorpius sported a new look as its middle star, Dschubba, suddenly and unexpectedly brightened to magnitude 1.9 from its usual magnitude of 2.3. The change was enough to make Dschubba quite plainly the brightest star in the naked-eye row of Graffias, Dschubba and Pi Scorpii, sometimes known as "The Crown of the Scorpion."
Editor's Note: Dschubba remains bright, and Joe will discuss what's going on with this object in a Spacewatch column on variable stars, due later this summer.
Main Spacewatch Page
More summer constellations, plus our Sky Calendar and more.
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