Astronomers Discover Record-Breaking 36-Billion-Solar-Mass Black Hole

Astronomers have identified a black hole so massive it could be close to the largest possible size in the Universe. Located in the galaxy SDSS J1148+1930, around 5 billion light-years away, this giant weighs in at 36.3 billion times the mass of our Sun.

For comparison, the Milky Way’s central black hole, Sagittarius A*, is just 4.3 million solar masses—a mere speck next to this cosmic monster. Scientists say this black hole belongs to an extremely rare category known as ultramassive black holes.

A Precise Measurement

According to astrophysicist Thomas Collett from the University of Portsmouth, this is among the top 10 largest black holes ever found and possibly the biggest. Unlike previous discoveries, which rely on indirect data, this measurement is considered highly accurate thanks to a unique method combining gravitational lensing and stellar motion analysis.

The Cosmic Horseshoe Connection

The black hole’s host galaxy is part of a rare space phenomenon called the Cosmic Horseshoe, where a massive galaxy’s gravity bends light from a more distant galaxy, creating an arc-shaped image. Studying this effect allowed scientists to estimate the galaxy’s mass and, by extension, the size of its central black hole.

Lead researcher Carlos Melo-Carneiro explained that this black hole is “dormant”, meaning it is not actively feeding on matter. Its presence was detected purely through its gravitational pull.

A Galactic Merger History

SDSS J1148+1930 is classified as a fossil galaxy, thought to be the remains of an ancient galaxy cluster whose members merged over billions of years. Each galaxy likely hosted its own supermassive black hole, which eventually combined into one enormous black hole—the 36-billion-solar-mass giant we see today.

A Clue to the Universe’s Limits

Theoretically, black holes could grow even larger, with the maximum estimated limit being about 50 billion solar masses. Discoveries like this help scientists understand how such colossal objects form and evolve.

“We’re seeing the final stage of galaxy and black hole formation,” Collett said.

The findings were published in the Monthly Notices of the Royal Astronomical Society and mark an important step in uncovering the mysteries of the most extreme objects in the cosmos.