Messier 75

This is Messier 75. It’s a globular cluster, a spherical collection of stars bound together by gravity. It’s around 67,000 light-years away. The majority of the cluster’s 400,000 stars are in its core, making it is one of the most densely packed clusters ever found. It’s extremely bright,180,000 times brighter than the Sun.

Image Credit: NASA / ESA

A Star Cluster in Another Galaxy

The clump of stars in the center of the picture is the globular cluster NGC 1898. It’s not in our galaxy. It’s near the middle of the Large Magellanic Cloud, a satellite galaxy of The Milky Way which contains a rich population of star clusters, making it an ideal laboratory for investigating star formation.

Image Credit: ESA / NASA


Messier 92 is one of the brightest globular clusters in the northern sky, but it is often overlooked by amateur astronomers because of its proximity to the even more spectacular Messier 13. It is visible to the naked eye under very good seeing conditions. Indeed, M92 is among the brightest clusters in terms of absolute magnitude as well as being one of the oldest clusters in the Milky Way.

Image Credit: ESA / NASA

NGC 3201

NGC 3201 is an oddball among the 150-or-so globular star clusters in the Milky Way. It is moving very rapidly through the galaxy, and its motion is retrograde, that is, it’s orbiting around the galactic core in the opposite direction of most of the stars in the galaxy. That’s led to speculation that it may have come from outside and have been captured.

Also, it contains a black hole which was revealed by the strange movements of a star being quickly flung around the massive, invisible singularity.

Image Credit: ESA / NASA