In the star cluster M15, astronomers measured the amounts of heavy elements. It turned out that the first stars, like a poorly stirred soup, had different amounts of these elements, while later ones were uniform. This hints at a turbulent and fast past for the cluster. Could this help us understand where gold in the Universe comes from?
Globular cluster M15 in our galaxy is an ancient stellar soup. Why do its stars differ in composition? By spreading starlight into a rainbow (spectroscopy), the Keck telescope revealed: in the first generation, heavy element abundances vary, while in the second they’re uniform. Like a poorly stirred soup: at first, you scoop up chunks or broth, but later it evens out. This means the gas for early stars was clumpy, and only later mixed.
This difference suggests the source of heavy elements ignited early and then quickly fizzled out — otherwise the unevenness would have persisted into the second generation. This fits the signature of neutron star mergers. And here’s a twist: the gold in your ring might have been forged in just such a burst, which “salted” M15’s gas over 10 billion years ago.
🎯 M15 boasts one of the densest stellar regions: in its core, stars can be closer together than the distance from Earth to Alpha Centauri.
🎬 Science fiction writers have often placed ancient civilizations in globular clusters — these stellar metropolises seem like the perfect setting for a long history.