Scientists Discover Three Supermassive Black Holes Hiding in One Galaxy 12.5 Billion Light-Years Away

Astronomers have made a remarkable discovery that could change our understanding of how giant black holes grew in the early universe. For the first time, scientists have found three actively feeding supermassive black holes inside a single distant galaxy.

The galaxy, known as J0148-4214, is located more than 12.5 billion light-years from Earth. Because its light has taken so long to reach us, astronomers are seeing this galaxy as it existed when the universe was only about 1.2 billion years old.

The discovery was made by an international team led by researchers from the Max Planck Institute for Extraterrestrial Physics (MPE). Using observations from NASA's James Webb Space Telescope (JWST), the researchers identified three black holes that are actively pulling in surrounding matter.

The findings, published in Astronomy & Astrophysics, provide an important new clue about how supermassive black holes became so large so quickly in the young universe.

Three Black Holes in One Galaxy

Black holes are regions of space where gravity is so powerful that even light cannot escape. Supermassive black holes can contain millions or even billions of times the mass of our Sun and are commonly found at the centers of large galaxies.

Finding one active black hole in a distant galaxy is already significant. Finding three in the same galaxy is extraordinary.

Two of the newly discovered black holes are located close to the center of J0148-4214. They are separated by only about 620 light-years. The third black hole is farther away, in the outer region of the galaxy, approximately 5,500 light-years from the center.

All three are actively feeding. They are surrounded by material that is falling inward under their enormous gravitational pull. As this material forms an accretion disk, it becomes extremely hot and produces intense radiation, making the black holes detectable even across enormous cosmic distances.

"This is the first evidence of three active black holes in a single galaxy in the distant universe," said Hannah Übler, research group leader at MPE and lead author of the study.

A Galaxy From the Early Universe

J0148-4214 is so distant that its light has traveled for around 12.5 billion years before reaching Earth.

The universe itself is expanding, and this expansion stretches the light traveling through space. As a result, the light from distant galaxies shifts toward longer, redder wavelengths, a phenomenon known as cosmological redshift.

The galaxy has a redshift of z = 5.02. This measurement allowed astronomers to determine its enormous distance and understand that they are observing the galaxy during a very early chapter of cosmic history.

At that time, the universe was still relatively young. Galaxies were forming, growing and colliding at a much faster pace than many do today.

This makes the discovery especially valuable because scientists are trying to understand how massive black holes could become so large so early in cosmic history.

How Did Scientists Find the Three Black Holes?

The black holes were identified through the distinctive signatures produced by rapidly moving hydrogen gas around them.

Gas near a black hole is affected by its powerful gravity. The hydrogen atoms in this material can move at extremely high speeds, leaving recognizable patterns in the light spectrum.

However, the two central black holes were so close together that ordinary observations could not clearly separate them.

To solve this problem, the researchers used a technique called spectro-astrometry. This method can detect extremely small shifts in the location of light coming from different parts of a galaxy.

Using this technique, scientists were able to determine that the complicated spectral signal from the central region was best explained by two separate active black holes, rather than a single object.

The observations also revealed the third black hole farther away from the center.

Their Masses Are Surprisingly Different

The three black holes are not equal in size.

Scientists estimate that they have masses of approximately:

• 80 million times the mass of the Sun

• 600,000 times the mass of the Sun

• 2 million times the mass of the Sun

The most massive black hole contains about 80 million solar masses. Interestingly, it is currently feeding at a lower rate than the much smaller black hole with about 600,000 solar masses.

The smaller black hole appears to be consuming material at an extremely high rate, even exceeding the maximum rate predicted by simple models of black hole growth, known as the Eddington limit.

The JWST observations also allowed researchers to estimate the total stellar mass of the galaxy at around 1.3 billion solar masses.

This means the black holes themselves represent a significant fraction of the galaxy's mass.

A Possible Black Hole Merger in the Making

The discovery could provide an important piece of evidence for theories about how galaxies and black holes grow.

Astronomers believe that the early universe was filled with rapidly evolving galaxies. Galaxies frequently came close to one another and sometimes merged. When galaxies merge, their central black holes can eventually move toward each other and form a massive black hole through a merger.

The two central black holes in J0148-4214 are expected to merge within the next few hundred million years.

Such a merger could eventually produce an even larger black hole.

According to Hannah Übler, these observations suggest that processes in the early universe were highly efficient at bringing massive black holes together. This could help explain why extremely massive black holes existed surprisingly early in cosmic history.

What Is the Third Black Hole Doing There?

The third black hole raises another fascinating question.

Because it is located away from the galaxy's center, scientists are considering several possibilities.

It could be the leftover result of an earlier galaxy merger. Alternatively, it may have been pushed away from the center by a powerful gravitational "kick" produced during a previous black hole merger.

Another possibility is that the black hole is currently moving inward toward the center and could eventually join the other two.

If this is the case, J0148-4214 could represent a rare snapshot of a galaxy containing multiple black holes at different stages of a merger process.

A New Window Into Black Hole Evolution

The discovery also demonstrates the importance of the James Webb Space Telescope for studying the distant universe.

In particular, the JWST's NIRSpec Integral Field Unit (NIRSpec-IFS) provided spatially resolved information that was crucial for the discovery.

Without this detailed information, researchers say they might have detected only one of the three black holes.

The finding shows that integral field spectroscopy could become an important tool for searching for multiple active black holes in distant galaxies.

It may also help scientists understand how black holes grew from relatively small objects into the enormous supermassive black holes observed in galaxies today.

A Glimpse of the Universe's Violent Past

The discovery of three active black holes in one galaxy is more than just a cosmic curiosity. It offers a rare glimpse into the chaotic environment of the early universe, when galaxies were growing rapidly and massive objects were frequently interacting.

The two central black holes are likely heading toward a merger, while the third may be the product of an earlier cosmic collision or could itself be moving toward the center.

Future observations and next-generation gravitational-wave observatories may eventually provide more direct evidence of such black hole mergers.

For now, J0148-4214 stands as a remarkable example of how dynamic the young universe was—and how much more there is still to discover about the mysterious giants lurking at the hearts of galaxies.

Reference: Hannah Übler et al, BlackTHUNDER: Evidence of three massive black holes in a z ∼ 5 galaxy, Astronomy & Astrophysics (2026). DOI: 10.1051/0004-6361/202557419