Mysterious cosmic ‘dots’ are baffling astronomers. What are they?

A consensus is emerging that the dots, sometimes called rubies, are an entirely new type of object in the Universe.

When the James Webb Space Telescope (JWST) looked back in time to observe the Universe’s earliest moments, it presented astronomers with something most peculiar: hundreds of ‘little red dots’ that inexplicably freckled the ancient cosmos.

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Nature 646, 779-780 (2025)

doi: https://doi.org/10.1038/d41586-025-03352-6

Correction 16 October 2025: An earlier version of this article contained an incorrect reference.

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