Webb Measures 50 Million Solar Mass Black Hole at 700 Myr

Astronomers have directly measured the mass of a supermassive black hole that existed when the universe was just 700 million years old, finding it is so large relative to its tiny host that it likely formed before the galaxy itself. The discovery, made using NASA’s James Webb Space Telescope, challenges long-held theories about how the universe’s first black holes grew.

The object, known as Abell 2744-QSO1 or QSO1, is a compact source of light classified as a “little red dot.” Its light has traveled for over 13 billion years to reach Earth. Researchers were able to study it in detail because its light is magnified and split into three separate images by the gravitational lensing effect of a massive foreground galaxy cluster, Abell 2744.

A team led by astronomers from the University of Cambridge and the University of Florence used the telescope’s Near-Infrared Spectrograph to map the motion and composition of hydrogen gas swirling around the object’s center. They found the gas exhibits Keplerian motion, orbiting a central point in the same way planets orbit the Sun. This pattern indicated that most of QSO1’s mass is concentrated at its core.

By applying the laws of gravity to...