The Hubble telescope has photographed Messier 15; one of the densest clusters of stars ever discovered.
Located about 35,000 light-years awa, Messier 15 is located inside the constellation Pegasus and is one of the densest globular clusters known. This photograph from the Hubble Telescope shows the cluster in all its spectacular glory:
The ESA says about Messier 15:
Both very hot blue stars and cooler golden stars can be seen swarming together in the image, becoming more concentrated towards the cluster’s bright centre. Messier 15 is one of the densest globular clusters known, with most of its mass concentrated at its core. As well as stars, Messier 15 was the first cluster known to host a planetary nebula, and it has been found to have a rare type of black hole at its centre.