Few people believe in astrology anymore, and that’s probably for the best. There was a time when most people thought that the stars controlled our destiny and that the signs of the Zodiac under which we were born determined the course of our lives.
If that were true, all the world’s attorneys should have been born under the sign of Libra, the Scales, because they have represented the rational and emotional balance out of which justice should arise. Yes, even lawyers have a patron constellation.
During June’s early evenings, Libra is situated straight south, about a third of the way up to the zenith, the highest point in the sky. Look for a large, kite-shaped arrangement of four relatively faint stars to the left and above the bright red star Antares in the constellation Scorpius.
Libra is in the Zodiac, the band of sky through which the planets, moon, and sun wander as they travel across the sky. The ancients believed the planets were physical manifestations of their gods, who could wander at will against the fixed starry background.
If you were born in late September or early October, then the sun was wandering through the patch of sky occupied by Libra on your birthday. Because it is the brightest of the wanderers, the sun was said to have the most significant influence on your future life.
Since Libra represents scales and scales represent balance, you are said to possess the qualities of calm emotional balance that would make you a good lawyer or game show host.
The sun appeared in Libra on the autumnal equinox, a day when daylight and nighttime are evenly divided. Here, then, was the balance point of heaven.
There are 12 zodiacal constellations. Libra is odd because it is the only inanimate object in the bunch. Everything else is a person or animal. Let’s see how it happened.
As we saw last week, the ancient Sumerians saw the stars of Libra as a scale or balance beam, probably because the sun appeared in Libra on the autumnal equinox.
By the time of the ancient Greeks, about 1,500 years later, that association had been superseded. The Greeks saw Libra as the claws of Scorpius, the Scorpion, located just to the southeast.
The Romans eventually reinstated the constellation’s “balance of heaven” association, but the association with the claws of Scorpius never disappeared entirely.
A remnant of the “claws” connection endures in the Arabic names for Libra’s two brightest stars.
Arab astronomers called the star farthest to the right “Zubenelgenubi” and the top star “Zubeneschamali,” the southern and northern claws.
Some modern astronomers still use those names and take great pride in how trippingly they fall from the tongue: Zuben-el-geh-NEWWWW-BEEEE.
However, modern astronomers who sacrifice imagination for ease of pronunciation call Zubenelgenubi “Alpha” and Zubeneschamali “Beta.” I’ll refer to them that way as well. Listen, you try typing “Zubenelgenubi” 15 times.
Alpha (whew, that was easy) is right on the line of the ecliptic, the path that the sun takes across the sky. Thus, around Nov. 7 every year, the sun passes over the star.
If you look at Alpha in a telescope, it turns out to be two stars. Such binary (or double) stars consist of two stars orbiting one another.
The bottom star in the kite shape, called Delta, is a special kind of double star called an eclipsing binary. Every 2.3 days, it dims in brightness for about 12 hours. That happens because the larger, but dimmer, star of the pair passes in front of its smaller, brighter companion.
The star Beta has an ancient mystery associated with it.
Eratosthenes was an ancient Greek astronomer who is famous because he first used astronomy to measure the size of the Earth. He (or someone impersonating him) wrote that Beta was brighter than the star Antares in nearby Scorpius. A few centuries later, the astronomer Ptolemy said it was as bright as Antares.
But to our modern eyes, Antares is much brighter than Beta. Has Beta gotten dimmer? Or has Antares increased in brightness as it prepares to flair into a red giant and die?
Modern astronomers believe that Antares must have changed. They speculate that Libra was called “the Scales” because Alpha and Beta are similar in brightness. Antares must have gotten brighter, or Libra would never have gotten its “balanced” reputation.
Tom Burns is the former director of the Perkins Observatory in Delaware.
