Hubble Reveals Hidden Glory of a Long-Lost Globular Cluster

A stunning image from NASA’s Hubble Space Telescope reveals a previously unexplored globular cluster, glittering with multicolored stars. Known as ESO 591-12, or Palomar 8, this cluster is a spherical gathering of tens of thousands to millions of stars, all tightly bound by gravity.

Globular clusters like this one formed early in their host galaxy’s life, in regions rich with gas and dust. Because all the stars formed from the same collapsing gas cloud, they usually share a similar age. In this image, red and blue stars appear scattered across the cluster — red indicating cooler stars and blue showing hotter ones.

Hubble gathered the data for this image during a project designed to resolve individual stars in all of the Milky Way’s globular clusters. Unlike ground-based telescopes, Hubble can distinguish individual stars in these densely packed systems. This effort is part of the Hubble Missing Globular Clusters Survey, which focuses on 34 confirmed Milky Way globular clusters that had remained unobserved by Hubble.

The survey aims to complete our record of globular cluster ages and distances across the galaxy. It also investigates key properties of clusters located in the galactic bulge or halo — regions still largely unexplored. These new observations will help astronomers understand the early stages of the Milky Way and the formation of globular clusters.