Black hole 36 billion times Sun’s mass discovered, likely the biggest ever in space

Scientists have identified what may be the most massive black hole ever observed, an ultramassive object with a mass of around 36 billion times that of the Sun.

Located roughly 5 billion light-years from Earth, the black hole sits at the center of a giant galaxy in the Cosmic Horseshoe system, named for the striking horseshoe-shaped ring of light formed by gravitational lensing, an effect where massive objects bend the light of more distant galaxies behind them.

The research, published August 7 in the journal Monthly Notices of the Royal Astronomical Society, details the use of gravitational lensing and stellar motion data to uncover and weigh the previously undetected black hole.

A Sleeping giant

This black hole is considered dormant, meaning it is not actively feeding on material and therefore does not emit the radiation typically used to identify black holes. That made it invisible to traditional methods, which rely on high-energy signals like X-rays.

Instead, researchers measured its mass by analyzing how its gravity warps space-time, bending light from a background galaxy into the Cosmic Horseshoe shape, and how stars within the galaxy orbit the core at extreme speeds, nearly 400 kilometers per second.

By combining both effects, the team was able to calculate the black hole’s enormous mass with high confidence.

A new way to find the universe’s heaviest objects

The project was led by Carlos AO Melo, a PhD candidate at the Universidade Federal do Rio Grande do Sul in Brazil, in collaboration with Dr. Thomas Collett of the University of Portsmouth in the UK.

The team used data from the Hubble Space Telescope and the MUSE instrument on the Very Large Telescope in Chile to carry out the analysis.

The galaxy harboring this black hole is a so-called “fossil group,” the result of a cosmic merger between multiple galaxies, which scientists believe may have led to the black hole’s formation. When galaxies merge, their central black holes are expected to eventually combine as well, producing an even larger object over billions of years.

This discovery adds weight to a growing body of evidence that supermassive black holes grow in tandem with their galaxies, and in some cases, may outgrow them entirely.

The Milky Way and its neighbor Andromeda are on a collision course expected to culminate in a similar merged galaxy several billion years from now, potentially forming a black hole just as massive.