Celestial monsters at the origin of globular clusters

Researchers have found strong evidence that supermassive stars can explain the anomalies observed in large clusters of stars. Scientists have found strong evidence that supermassive stars existed within globular clusters when they formed 13 billion years ago. Here, an image of the globular cluster M13, 22 000 light years from Earth, consisting of a million stars squeezed into a space 150 light years across. HST STScI NASA ESA - Globular clusters are the most massive and oldest star clusters in the Universe. They can contain up to 1 million of them. The chemical composition of these stars, born at the same time, shows anomalies that are not found in any other population of stars. Explaining this specificity is one of the great challenges of astronomy. After having imagined that supermassive stars could be at the origin, a team from the Universities of Geneva and Barcelona, and the Institut d'Astrophysique de Paris (CNRS and Sorbonne University) believes it has discovered the first chemical trace attesting to their presence in globular proto-clusters, born about 440 million years after the Big Bang. These results, obtained thanks to observations by the James-Webb space telescope, are to be found in Astronomy and Astrophysics . Globular clusters are very dense groupings of stars distributed in a sphere, with a radius varying from a dozen to a hundred light years. They can contain up to 1 million stars and are found in all types of galaxies. Ours is home to about 180 of them. One of their great mysteries is the composition of their stars: why is it so varied?