Roberto J. Assef

Quasar W2246–0526 is a beacon lit when the universe was just 1.3 billion years old. Its light has traveled 12.8 billion years to reach us, yet even at such a distance, astronomers have spotted what had eluded them for decades: the gravitational shadow of a black hole.

Two houses with identical facades but different interior layouts: from the outside the V-shaped spectrum looks the same, but inside there are different light sources and different amounts of dust. That is exactly how the two populations of distant galaxies that astronomers have long confused appear.

The kitchen of a distant galaxy isn't limited to its bright disk. Around every star system, there's an invisible cloud of gas, like steam above a pot of soup. Astronomers peeked into this steam around galaxies that appear as they were just one and a half billion years after the Big Bang.

In 1963, Maarten Schmidt unraveled the nature of quasars — distant active nuclei outshining entire galaxies. Since then, we've learned that at their hearts lurk supermassive black holes, converting infalling matter into blinding light.

In 2024, the Hephaestus project sifted through millions of stars and flagged a few dozen suspicious ones: they shone brighter in the mid-infrared than a normal red dwarf should. Two of these candidates, labeled D and E, looked especially tantalizing, as if an invisible heater were working next to the star.