Not long after the James Webb Space Telescope began science operations in July 2022, breathless headlines proclaimed that observations of distant galaxies were “breaking theories of cosmic evolution.” Astronomers had found galaxies that appeared much brighter than expected. If all of that light came from stars, then those galaxies would have formed so many stars, so quickly, that the leading theory for the universe’s formation and evolution could not explain them.

New research finds that some of those early galaxies are in fact much less massive than they first appeared. Much of their light came, not from stars, but from a hot accretion disk surrounding a supermassive black hole.

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