CAMBRIDGE — Researchers using NASA’s James Webb Space Telescope have directly measured a supermassive black hole in the early universe that appears to predate its host galaxy, challenging classical theories of black hole formation. The black hole, located in an object known as Abell2744-QSO1 (QSO1), existed just 700 million years after the Big Bang and has a mass of roughly 50 million times that of the Sun.

QSO1 is only 1,300 light-years across, and its light has traveled more than 13 billion years to reach Earth. Its visibility was enhanced by gravitational lensing from the galaxy cluster Abell 2744, also known as Pandora’s Cluster, which magnified and produced three distinct images of the object. Observations from Webb’s Near-Infrared Spectrograph (NIRSpec), using its integral field unit, allowed researchers to map the motion of hydrogen gas surrounding the black hole.

The gas exhibits Keplerian motion—rotating around a central point much like planets orbit the Sun—indicating that most of QSO1’s mass is concentrated in the black hole at its core. “This is important because it tells us that most of the mass of QSO1 is concentrated in the black hole at the center,” said Cambridge graduate student Ignas Juodžbalis. “If the mass were more distributed, as it would be if there were a lot of stars, the gas would not have this perfect Keplerian rotation.”

The black hole constitutes at least two-thirds of QSO1’s total mass, a proportion thousands of times greater than in nearby galaxies, where supermassive black holes account for only a tiny fraction of their host’s mass. Spectroscopic analysis also revealed that QSO1’s gas is composed almost entirely of hydrogen and helium, with a metallicity less than 0.5% of the Sun’s, making it one of the most chemically pristine environments ever observed.

“This is a phenomenal result. It is the first direct measurement of a black hole mass within the first billion years after the Big Bang, and it is consistent with the previous measurements,” said Cosimo Marconcini of the University of Florence. Roberto Maiolino of the University of Cambridge called the finding “a paradigm shift, a total revisiting of the classical scenarios of how black holes form and grow.” The team suggests the black hole may have formed within the first second of the Big Bang, before its host galaxy assembled around it.