NASA Hubble Telescope Captures Spectacular New Image of Brilliant Globular Cluster

The NASA Hubble Space Telescope has captured a new, spectacular image of the globular cluster Messier 15, a gathering of very old stars that orbits the center of the Milky Way. Holding over 100,000 stars, this cluster holds the promise of hiding a rare type of black hole at its very center.

Messier 15 is located about 35,000 light-years away from the constellation Pegasus. It's one of the oldest globular clusters known with an age of around 12 billion years. Globular clusters are roughly spherical groups of stars that orbit the core of a galaxy. The Milky Way alone has over 150 of these starry satellites, including Messier 15.

This latest image of the cluster is the best ever taken, revealing spectacular new details to astronomers. Very hot blue stars and cooler golden stars swarm together in this picture, becoming more concentrated toward the cluster's bright center. Messier 15 is actually one of the densest clusters known, and most of its mass is concentrated at its core.

Yet there's something dark and mysterious lurking at the heart of this brilliant cluster. In 2002, Hubble discovered that there was something at its center, though astronomers still haven't determined what that something is yet. It could be a collection of dark neutron stars, or an intermediate-mass black hole. The black hole, though, is the likeliest explanation.

Intermediate-mass black holes are thought to form either from the merging of several smaller, stellar-mass black holes, or as a result of a collision between massive stars in dense clusters. A third possibility is that they were formed during the Big Bang. In terms of mass, they lie between the more commonly found stellar-mass and supermassive types of black hole, and could tell us a little bit more about how black holes grow and evolve within clusters.

That's not all that this cluster harbors, though. Messier 15 is also known to house a planetary nebula, Pease 1. In fact, this is the first globular cluster known to contain one of these objects. You can spot the nebula as the bright blue object just to the left of the cluster's center.

The new image shows astronomers a little bit more about Messier 15. More specifically, it reveals new details that could aid the hunt for the potential black hole at its heart. It also shows a spectacular view of one of the most beautiful objects in our universe.