NGC 3293 is an open star cluster located about 8,000 light years away towards the constellation Carina. It contains almost 50 stars. The younger, blue stars likely formed around 6 million years ago, while older redder stars formed about 20 million years ago, still young by our Sun’s 4.6 billion year old age.
The stars in open clusters usually form about the same time, from the same molecular cloud of material, and thus have similar compositions. This allows astronomers to examine questions of stellar evolution. The cluster is held together by the gravity of the stars, which is not enough to hold it together through other gravitational interactions. Eventually, the cluster dissipates, usually lasting only a few hundred million years.
Image from ESO, information from ESO and NASA.