JWST Uncovers Earliest Pair of Supermassive Black Hole Quasars, Defying Cosmic Dawn Models

A pair of black holes so massive and so close, seen just 900 million years after the Big Bang, has left astronomers scrambling. The twin quasars, named J1602+4228AB and nicknamed Nāpōwawāʻenakaulua, shine because each black hole feeds on a swirling accretion disk that glows brighter than its host galaxy.

The pair sits only 18,100 light‑years apart—about one‑fifth the Milky Way’s diameter—and weighs 1.5 billion and 400 million solar masses. That makes it the most compact quasar pair found during Cosmic Dawn, a time when models predict black holes should still be tiny. The existence of such massive objects so early challenges the idea that black holes need a billion years to grow.

The discovery came from JWST’s Aether survey, which has already catalogued 200 quasars, nearly half of all known early‑universe quasars. While browsing the data, astronomers noticed J1602+4228A had a companion, and the Gemini North telescope resolved the two thanks to perfect weather on Maunakea. Our read: Nāpōwawāʻenakaulua offers a laboratory for studying how the first massive galaxies and their central black holes assembled through direct interactions.

Future JWST observations may rewrite how quickly black holes can grow in the universe’s first billion years.