Astronomers have discovered the most distant dormant black hole ever detected, offering a rare glimpse into the early universe and how massive black holes grew alongside their host galaxies.
The black hole lies at the center of a galaxy called MRG-M0138, located more than 10 billion light-years from Earth.
This means astronomers are seeing it as it appeared when the universe was only about 3 billion years old—roughly one-quarter of its current age.
The newly measured black hole has an astonishing mass of about 6 billion times that of the Sun.
It is also the most distant dormant black hole ever identified, about 15 times farther away than the previous record holder.
The discovery was made by an international team of astronomers using data from NASA’s James Webb Space Telescope (JWST).
Unlike many supermassive black holes that actively consume gas and shine brightly, this one is essentially “sleeping.”
Active black holes are relatively easy to find because gas falling into them becomes extremely hot and emits enormous amounts of light. These bright objects, known as quasars, are among the most luminous objects in the universe.
However, dormant black holes are much harder to detect because they produce little or no visible radiation. Instead, scientists must search for their gravitational effects on nearby stars.
To uncover this hidden giant, researchers tracked the motions of stars orbiting near the galaxy’s center.
The stronger the black hole’s gravity, the faster nearby stars move. By carefully measuring these stellar motions, the team was able to calculate the black hole’s mass.
This method, known as stellar dynamics, has been used successfully to measure black holes in nearby galaxies, including the supermassive black hole at the center of the Milky Way. However, this is the first time the technique has been applied to a galaxy located so far away in cosmic history.
Observing such distant stars would normally be impossible, but nature provided the researchers with a powerful helping hand. A massive galaxy located between Earth and MRG-M0138 acts like a giant cosmic magnifying glass through a phenomenon called gravitational lensing.
The gravity of the foreground galaxy bends and amplifies the light from the distant galaxy behind it, making it appear about 30 times larger. This allowed the team to study details that would otherwise be far beyond the reach of current telescopes.
The researchers found that not only is the black hole inactive, but the host galaxy has also stopped forming new stars. This suggests the galaxy experienced a dramatic past.
Scientists believe that when the black hole was younger and rapidly growing, it likely behaved like a powerful quasar.
During that active phase, it may have released enormous amounts of energy that heated up or expelled the gas needed to create new stars. As a result, both the black hole and the galaxy eventually entered a quiet state.
The discovery provides valuable clues about the relationship between galaxies and their central black holes during the universe’s early years. Astronomers hope future observations with JWST and other telescopes will uncover many more dormant black holes from this distant era.
By studying these hidden giants, researchers may finally understand how supermassive black holes influenced galaxy growth and how some sleeping black holes can awaken again when fresh material becomes available.
