The Butterfly Cluster — Cluster of Stars

Looking like a butterfly with spread wings, the appropriately named Butterfly Cluster is located approximately 1600 light-years away towards the constellation of Scorpius (the Scorpion).

About 100 million years old and 20 light-years across, the Butterfly Cluster is an open cluster containing many young hot blue stars. The brightest star in the cluster is the extremely massive supergiant BM Scorpii (also known as HD 160371), its orange hue making a delightful contrast to its bluish neighbourhood.

The jury is still out on who actually noticed this cluster for the first time. Some say it is the Greek astronomer Ptolemy in the first century AD who recorded it originally while observing a neighbouring object now called Messier 7. The official credit for now, however, goes to the Italian astronomer Giovanni Battista Hodierna who recorded the Butterfly Cluster in 1654. A century later, it was rediscovered by several astronomers, and in 1764, Charles Messier added it as the sixth entry in his famous catalogue (Messier 6).