In 2023, the James Webb Space Telescope revealed something strange: the distant reaches of the universe are filled with “little red dots” that astronomers still can’t quite explain.

But a new paper I coauthored, published today in Nature Astronomy, might have found the key to understanding their nature.

It turns out these little red dots might actually be evidence of the earliest supermassive black holes. And they could hold clues to how stars and galaxies formed in the earliest years of the universe.

Discovering the unexpected

The James Webb Space Telescope is the most powerful telescope ever made and has enabled the discovery of things we had never imagined.

This is the case for little red dots. Their name is a simple derivation of their appearance: they appear as very small compact dots that are “red” in colour (noting the James Webb Space Telescope sees in the infrared).

These objects are extremely distant, and are seen at an epoch when the universe is only around one billion years old (based on the time it takes the light to reach us).

Their compact size and extreme distance mean that most of their light comes from an area smaller than 2% of the size of our Milky Way........

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