Cosmic Gems Arc: Proto-Globular Star Clusters Form at Extreme Density
c. 13.36 Billion years ago · Prehistoric
Approximately 460 million years after the Big Bang, five gravitationally bound star clusters formed within a small galaxy later designated SPT0615-JD1. Each cluster contained roughly one million solar masses compressed into volumes only one parsec across, producing stellar surface densities approximately 1,000 times higher than typical young star clusters observed in the modern universe. JWST resolved these structures in 2024 through gravitational lensing by galaxy cluster SPT-CL J0615-5746. The clusters represent the earliest known proto-globular clusters, demonstrating that complex bound stellar structures assembled far earlier than standard models predicted.
Topics
cosmologystar formationglobular clustersgalaxy formationgravitational lensing
Connected Events — 4 Connections
The first generation of stars produced the heavy elements and radiation that enabled dense cluster formation just a few hundred million years later First Star formed
The Cosmic Gems proto-clusters at 460 Myr represent the earliest known precursors to mature globular clusters like HP 1, which formed roughly 500 million years later in the Milky Way's bulge Formation of Globular Cluster HP 1 in the Milky Way Bulge
The Cosmic Gems clusters formed within one of the earliest galaxies, demonstrating that dense bound stellar structures were assembling contemporaneously with the first galactic structures Formation of First Galaxies: Birth of Stellar Structures
The intense ultraviolet radiation from dense star clusters like the Cosmic Gems contributed to the reionization process that ended the Cosmic Dark Ages End of Cosmic Dark Ages: Universe Becomes Transparent
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