Rigel is one of the more impressive stars in our part of the galaxy: It’s the seventh-brightest star in the night sky, it’s many times the size and mass of the Sun, and it’s fated to explode as a supernova.

But a closer look shows that Rigel is even more impressive than it seems. It appears to be a system of at least four stars – the one that’s visible to the eye alone, plus three others that are grouped fairly close together.

The companions include a binary – two stars locked in a tight orbit around each other – plus a third star that’s farther away.

All three companions are three to four times the mass of the Sun. That puts them in the top one percent of all stars in the galaxy.

The stars in the binary orbit each other once every 10 days. At the system’s distance of more than 850 light-years, not even the biggest telescopes can see them as individual stars. Instead, astronomers use special instruments to tell them apart. The third star is far enough from the others that it’s easy to see on its own.

This triplet of stars is about a quarter of a light-year from the bright star that’s visible to our eyes alone. At that separation, it would take at least 24,000 years for the bright star and the triplets to orbit each other.

Rigel is the foot of Orion the hunter. The constellation is low in the eastern sky at nightfall. Look for its three-star belt extending upward from the horizon. Rigel is to the right of the belt.

Script by Damond Benningfield