JWST Spots Oldest Black Hole Ever Detected in Early Universe

The James Webb Space Telescope (JWST) has fundamentally altered the timeline of cosmic history by identifying the oldest supermassive black hole ever confirmed. Located at the center of the galaxy GN-z11, this celestial giant dates back to just 400 million years after the Big Bang. This discovery challenges long-held theories about how the universe formed and suggests that black holes grew much faster and earlier than astronomers previously thought possible.

The Discovery in Galaxy GN-z11

For years, the galaxy GN-z11 was a point of fascination for astronomers. Initially identified by the Hubble Space Telescope, it held the record as one of the oldest and most distant galaxies known to man. However, it was not until the JWST turned its powerful infrared instruments toward this ancient cluster that the true nature of its core was revealed.

A team led by Professor Roberto Maiolino from the Cavendish Laboratory and the Kavli Institute of Cosmology at the University of Cambridge analyzed the light spectrum coming from the galaxy. They discovered signatures of an extremely dense, hot gas swirling around the center. These are the tell-tale signs of an accretion disk—the halo of matter feeding a supermassive black hole.

Key details of the discovery include:

• Age: The black hole existed approximately 400 million years after the Big Bang.
• Mass: It is roughly 1.6 million to 6 million times the mass of our Sun.
• Location: It resides 13.4 billion light-years away in the constellation Ursa Major.
• Publication: The findings were published in the scientific journal Nature in early 2024.

Why This Breaks Standard Physics

The existence of a black hole this massive, this early in the universe, presents a major problem for standard cosmological models. Under the traditional understanding of stellar evolution, black holes begin when a massive star collapses. These “stellar-mass” black holes are usually only 10 to 100 times the mass of the Sun.

To grow from 100 solar masses to several million solar masses usually takes billions of years of feeding. However, the black hole in GN-z11 achieved this size in less than 400 million years.

Professor Maiolino described the anomaly by comparing it to seeing a family walking down the street where the toddler is six feet tall. It is theoretically possible for the child to grow that tall eventually, but it should not happen that early in their lifecycle. This discrepancy forces scientists to reconsider two main theories of black hole formation:

1. Super-Eddington Accretion: The black hole is “binge eating.” The Eddington limit is a physical rule that defines the maximum rate at which a black hole can consume matter without the radiation pushing the food away. This specific black hole appears to be devouring matter at five times the Eddington limit.
2. Heavy Seeds: The black hole may not have started from a single dying star. Instead, vast clouds of primordial gas might have collapsed directly into a massive black hole, starting the process with a “seed” that was already tens of thousands of times the mass of the Sun.

The "Vampire" Effect on Its Host Galaxy

While the black hole is fascinating on its own, its relationship with its host galaxy, GN-z11, is destructive. The JWST data suggests that the black hole is harming the galaxy’s development.

As the black hole consumes gas at such a high velocity, it ejects powerful winds and radiation. These outflows push away the cold gas required to form new stars. In astronomy, this is known as “quenching.”

Because GN-z11 is a small galaxy—about 100 times smaller than the Milky Way—it is easily overwhelmed by the energy of its supermassive core. The black hole is effectively starving the galaxy to death by removing the fuel needed for stellar birth. This supports the theory that supermassive black holes in the early universe played a dominant role in shaping, and sometimes destroying, their host galaxies.

How JWST Made This Possible

The Hubble Space Telescope could not see this black hole because the expansion of the universe stretches light into the infrared spectrum. This “redshift” makes distant objects invisible to optical telescopes.

JWST was built specifically for this purpose. Its primary instruments involved in this discovery were:

• NIRCam (Near-Infrared Camera): Detected the faint galaxy and helped target the specific region of the sky.
• NIRSpec (Near-Infrared Spectrograph): This instrument broke the light down into its constituent colors (spectrum). By analyzing the “gaps” and “spikes” in the spectrum, researchers identified highly ionized neon and carbon, which indicated the presence of the intense high-energy radiation typical of a feeding black hole.

This discovery marks a new era for the Webb telescope. Astronomers believe this is likely just the first of many such ancient black holes it will uncover. If these massive objects are common in the early universe, the entire timeline of cosmic dawn may need to be rewritten.

Frequently Asked Questions

Is this black hole bigger than the one in the Milky Way? Not necessarily bigger, but surprisingly comparable. The black hole at the center of the Milky Way, Sagittarius A*, is about 4 million solar masses. The black hole in GN-z11 is estimated between 1.6 and 6 million solar masses. The shock is that GN-z11’s black hole reached this size nearly 13 billion years before ours did.

What is the “Eddington Limit”? The Eddington Limit is the theoretical maximum brightness a star or accretion disk can achieve before the outward pressure of its radiation overcomes the inward pull of gravity. If a black hole feeds faster than this limit, it usually blows the food away. The GN-z11 black hole seems to be breaking this rule.

Can we see the black hole itself? No. By definition, a black hole absorbs all light. What JWST detected is the accretion disk, a glowing ring of gas and dust spinning around the black hole, and the chemical signatures of that gas being superheated.

Will the black hole eventually eat the whole galaxy? It is unlikely to eat every star, but it will stop the galaxy from growing. By blowing away the gas needed to make new stars, the black hole ensures the galaxy will eventually fade as its existing stars die out.