Blue Gems

Brilliant blue stars highlight this view of Messier 47, a star cluster roughly 1,600 light-years from Earth in the southern constellation Puppis. These stars are young, hot, and massive. They will live short lives, however, quickly evolving into red giants or supergiants (a few massive young stars have already done so), then expiring. M47 is near another cluster, Messier 46. Both of them appear not far from Sirius, the brightest star in the night sky. [European Southern Observatory]