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September 2, 2021

Every star you see in the night sky has many names: proper names, Greek-letter names, and names that look like phone numbers. And the names keep getting more complicated.

Consider Dabih. It’s in Capricornus, which is in the southeast at nightfall. Dabih is near the right point of a wide triangle that outlines the sea-goat. Right now, the star is above the bright planet Saturn.

Dabih is a system of at least five stars. Or it used to be. Now it’s just a single star. The other stars didn’t go away. They just aren’t called Dabih any more — at least not officially.

A telescope shows Dabih as two stars. The brighter one is known as Dabih Major. But it’s also known as Beta-1 Capricorni and Beta Capricorni A. The other one is Dabih Minor, Beta-2 Capricorni, and Beta Capricorni B.

There’s more to the system than meets the eye, though. “B” consists of two stars, while “A” has three.

The group that names astronomical objects has been assigning official proper names to stars. Most of the names have been around for centuries — like Dabih. For systems that contain multiple stars, though, the group decided to assign the classical name to only one star. So “Dabih” was given to one of the stars of system A.

On many star charts, though, the name still applies to the entire system. So many skywatchers are likely to keep thinking of the point of light that’s visible to the eye as Dabih — one of many names for a crowded star system.

Script by Damond Benningfield

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