The ‘Z’ stars, tongue twisters of the night sky
One of the faintest zodiac constellations in the Butler night sky is the constellation Libra, the Scales.
Like most constellations, good luck seeing it for what it’s supposed to be. It allegedly outlines scales, the universal symbol of justice.
Libra only has two stars you can realistically see with the naked eye, and the names of those stars are the toughest tongue twisters you’ll ever come across. They are Zubeneschamali, pronounced “zuba-nes-sha-molly,” and Zubenelgenubi, pronounced “zoo-been-nel-jay-new-bee.”
Just try to say these names 10 times as fast as you can. I hope you don’t bite your tongue! I just call them the “Z” stars.
Libra and the Z stars are visible in the very low southern sky after evening twilight. You really need a good view of the southern horizon, one that doesn’t have much of a tree line.
The best way to locate Libra and the Z stars is to use the three stars that outline the head of the adjacent constellation Scorpius, just starting to rise above the southeast horizon. Look for three moderately bright stars evenly spaced in a short diagonal line. They should be easy to see.
Just to the right of those stars is Libra with Zubeneschamali and Zubenelgenubi. The Z stars will be oriented diagonally, with Zubeneschamali on the upper left and Zubenelgenubi on the lower right. For sure, they’ll be the brightest stars in that immediate area.
These tongue-twisting Z stars are Arabic names that roughly translate to English as the northern claw and southern claw respectively.
What do “claw” stars have to do with the scales of justice? Absolutely nothing!
As it turns out, the constellation Libra was invented by the Roman Empire’s Julius Caesar around the time of Christ. Originally, the Z stars of Libra were seen as the claws of the neighboring constellation Scorpius the Scorpion.
Since he was an all-powerful emperor, Caesar decreed that the claws of Scorpius be hacked off and made the Z stars and a few others around them into the new constellation Libra the Scales. Nobody dared to disagree.
As with many stars, Zubenelgenubi appears to the naked eye as a single star, but like many stars, it’s actually a binary system made up of two stars, revolving around each other, 77 light-years away from Earth. If you’re new to this column, light-years are the easiest way to describe the incredible distance to the stars. A light-year is defined as the distance a beam of light travels in a year, about 5.8 trillion miles. Zubenelgenubi is nearly 440 trillion miles away!
Zubeneschamali is even farther away, 185 light-years distant. It’s a blue giant star well over 4 million miles in diameter. Our own sun isn’t even a million miles across. Its surface temperature is believed to be over 22,000 degrees, more than twice as hot as our sun.
Before you catch your nightly Z’s, try to catch the Z stars of Libra in the low southern sky just after evening twilight. Don’t feel bad if you can’t pronounce them though. I’ve been stargazing for over half a century and still disastrously stumble on them. They’re the ultimate mental block for me.
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul. He is also the author of “Stars: a Month by Month Tour of the Constellations,” published by Adventure Publications and available at bookstores and at adventurepublications.net. Contact him at mikewlynch@comcast.net.
