Steven L. Finkelstein

The James Webb Space Telescope spotted bright points of light from an era just 100–300 million years after the Big Bang. At first they were taken for distant galaxies, but now a hypothesis suggests they might be lone fireworks — explosions of the very first stars.

A massive galaxy cluster acts as a giant lens. Its gravity warps the fabric of space, and the light of distant objects, bending around this curvature, is amplified and split into multiple images.

Thanks to gravitational lens — an effect predicted by Fritz Zwicky, where a galaxy cluster acts like a magnifying glass — the James Webb Space Telescope spotted two red dots in a galaxy 800 million years after the Big Bang.

Imagine a city where a skyscraper and a huge park are being built at the same time. The skyscraper grows upward, and the park expands outward. Both processes are fast and get in each other's way, but in the end they are meant to become a single whole. That's the situation in galaxy GNz7q: a black hole grows at the center while new stars burst to life around it.

Immediately after the Big Bang, an idea championed by Georges Lemaître, the cosmos was a dark broth of hydrogen and helium. Then the first stars ignited — enormous, dazzlingly bright and hot, like sparks from a cosmic bonfire.

Heir to the ideas of Edwin Hubble, the James Webb Space Telescope has peered back to an era when the expansion of the universe was still picking up speed. At redshifts z>4, it spotted bizarre objects—"Little Red Dots" (LRDs).

The Universe is less than a billion years old, yet at its centers already sit black holes with masses of a billion suns. According to the conventional picture, they grew by voraciously devouring matter, but calculations show that 'feeding' must have been almost continuous, while visible quasar flares last only a few million years. So where does all the accreting fuel go?

A marathon lasting 13 billion years started with different weights. A hundred solar masses — lighter than some gas clouds. A hundred thousand — gravitational dominance, comparable to an elephant among kittens. That's what black hole seeds looked like, ones that by our time should have turned into supermassive giants.

The night sky is full of deceptive lights. Astronomers were searching for galaxies that ignited in the first few hundred million years after the Big Bang: their light has traveled to us for nearly 13 billion years. Six faint smudges were selected from images taken by the Hubble and Spitzer space telescopes.

In a distant galaxy, light from hot gas should reveal its composition. The James Webb Telescope split that light into a spectrum, and astronomers saw: oxygen lines too weak.