Hubble maps forgotten star cluster ESO 591-12, unlocking the Milky Way’s ancient secrets
NASA’s Hubble Space Telescope has captured a breathtaking new image of a rarely studied globular cluster, shedding light on the Milky Way’s oldest and most mysterious regions. The newly revealed cluster, ESO 591-12, is adorned with glittering multi-hued stars that reveal secrets about the galaxy’s early history.
Globular clusters like ESO 591-12 are dense, spherical groupings of stars — often containing the mass of about 100,000 suns — that orbit the center of their host galaxy. These stars are typically nearly the same age, having formed from a single collapsing gas cloud. In the image released by NASA, the stars appear in striking red and blue hues, which correspond to their temperatures: red indicating cooler stars, blue representing hotter ones.
Filling the gaps in the Milky Way’s stellar story
The observation of ESO 591-12 is part of the Hubble Missing Globular Clusters Survey, an ongoing initiative aimed at imaging 34 Milky Way clusters that had never before been studied by the space telescope. This survey seeks to create a detailed database of the ages, distances, and stellar compositions of all known globular clusters in the galaxy.
According to NASA, Earth-based telescopes have historically struggled to resolve individual stars in such densely packed environments. Hubble’s superior resolution, however, allows astronomers to trace stellar movements and unlock clues about their histories and formation.
Ancient cosmic fossils
These ancient clusters act as cosmic fossils, preserving conditions from the primordial universe. Studying them gives scientists insight into how the Milky Way formed and evolved over billions of years. ESO 591-12, in particular, sits in the galaxy’s bulge or halo — areas believed to hold key information about the Milky Way’s earliest epochs.
The latest findings demonstrate how advanced, space-based observatories continue to peel back the dark, dusty layers of our galaxy, revealing new chapters in the story of the universe’s evolution. As NASA’s report notes, even star clusters hiding in plain sight, like ESO 591-12, contribute important pieces to the cosmic puzzle.
Hubble’s ongoing work ensures that more of these hidden stellar gems are brought into focus, enriching our understanding of the universe — and our place within it.