Sandro Tacchella

Astronomers refined the mass of three extremely distant galaxies using Webb, and it turned out: invisible dust can distort our estimates more than we imagined, but even with corrections, two galaxies remain monstrously massive for their young age.

Near the galaxy GN-z11, seen just 400 million years after the Big Bang, the James Webb Space Telescope spotted a bright spot. It glows with hot helium — such radiation can only come from very massive stars devoid of heavy elements, that is, the first generation. If confirmed, we are seeing for the f

For decades astronomers puzzled over mysterious anti-correlations of light elements in globular clusters. New research based on high-resolution cosmological simulations shows: the chemical anomalies could have arisen long before the birth of the cluster's first stars—in giant gas clouds. This scenar