Moon and Antares

Antares is much more than just bright and beautiful. The orange heart of the scorpion is among the biggest and heaviest stars in the galaxy. And it’s the dominant member of a vast complex of stars, gas, and dust.

The complex is known as the Scorpius-Centaurus OB Association. It consists of three big clumps. Each clump contains thousands of stars, of all sizes. But the clumps are dominated by classes O and B — hence the association’s name. These are the hottest, brightest, and most massive of all stars, shining blue and white. They burn out in a hurry, so they die young. Many of them explode as supernovae.

The clumps range in age from about 10 million to 17 million years. Each one consists of several smaller groups of stars that were born together.

The earliest groups may have helped give birth to later groups. Strong winds from the hot, young stars, along with shock waves from the supernovae, could have squeezed nearby clouds of gas and dust. That would have caused the clouds to break into smaller clumps, which then collapsed to form stars.

Antares was born as a class O star. But it’s nearing the end of its life. As a result, it’s puffed up to gigantic proportions. That’s caused its outer layers to get cool and red, so now it’s class “M.” Even so, it’s still the most impressive member of an impressive collection of stars.

Look for Antares directly below the Moon as darkness falls — an orange supergiant at the heart of Scorpius.

Script by Damond Benningfield