Royalty creeps across the southern sky on autumn nights: Fomalhaut, the brightest star of Piscis Austrinus, the southern fish. To the people of ancient Persia, it was one of four “royal” stars, along with Aldebaran, Regulus, and Antares. Each star ruled the sky during a different season. For Fomalhaut, it was the autumn sky.

Fomalhaut probably was a pretty easy choice. It’s the only bright star in a large region of the sky. And at this time of year, it’s in view pretty much all night.

Fomalhaut also was considered the protector of the winter solstice. About 5,000 years ago, the star aligned in the same direction as the Sun at noon on the solstice.

The Fomalhaut system appears to consist of at least three stars. The brightest is Fomalhaut A – the one that’s visible to the unaided eye. The star is about twice as big and heavy as the Sun, and quite a bit brighter. It’s about 25 light-years away.

A giant disk of dust encircles the star. For a few years, it looked like there might be a planet inside the disk. Astronomers even gave it a name: Dagon. But it turned out to be just a big clump of dust – the likely debris from a collision between two big asteroids.

Fomalhaut stands quite low in the southeast as the sky gets good and dark, and due south around midnight. Don’t confuse it with brighter Saturn, well to its upper left. Fomalhaut is in view all night – a royal star for autumn nights.

Script by Damond Benningfield