This is a young super star cluster known as Westerlund 1. It’s the home of one of the largest stars yet found. Westerlund 1-26 is a red supergiant with a radius over 1,500 times that of our sun. Indeed, it’s sometimes referred to as a hypergiant star. If Westerlund 1-26 were at the center of our solar system, it would extend out beyond the orbit of Jupiter.
The Westerlund 1 cluster is relatively young in astronomical terms, around three million years old. The Sun is around 4.6 billion years old.
Image Credit: NASA / ESA