Alex McColgan

how many stars a galaxy contains, and how much dust these stars can produce.

In late 2024, Kaitlyn Casey and her team at the University of Texas in Austin calculated their expected stellar population based on the optical light detected from the little red dots.

But once they applied the star to dust ratio, their stomachs dropped.

Their calculations only yielded 1% of the dust needed to explain the redness they were seeing.

And now, a shortfall of two orders of magnitude could only mean one of two things.

Either the well-established dust formation models are wrong, or the main light source of these little red dots wasn't stars.

The second problem was the brightness.

To explain the overall brightness of little red dots using just stars, you'd need an impossibly high density of stars in a very compact region of space.

They'd only be a few astronomical units apart, but this close together, stars would be colliding and merging all the time.

and the gravitational dynamics would be far too unstable.

What's more, these little red dots don't look like normal galaxies.

Usually we can see some kind of internal structure, but even though James Webb has the highest resolution of any telescope we've ever built, the little red dots just appear as points of light.

Single dots in the night sky, like stars appear to the naked eye.

So either the little red dots are really tiny, or their light is so dominated by a single central source that it drowns out any other surrounding signature that might exist.

Which brings us to the second theory.

What if little red dots aren't star-filled galaxies at all?

What else could explain their properties?

Problems like this require sifting through mountains of data.

Searching for vital information in all that noise can be worse than finding a needle in a cosmological haystack.

It's not a task to be attempted with an Excel spreadsheet.