a black hole 36 billion times the mass of our Sun

 a black hole 36 billion times the mass of our Sun

Astronomers have uncovered a cosmic heavyweight that’s pushing the boundaries of what nature can build a black hole 36 billion times the mass of our Sun. This monster resides 5 billion light-years away at the heart of the Cosmic Horseshoe, a rare gravitational lens system where a foreground galaxy bends the light of one far behind it into a stunning arc.

What makes this find extraordinary is its silence no bright jets, no radiation, no telltale glow of devouring matter. Instead, its presence was revealed purely through its gravity warping the light of a background galaxy and whipping nearby stars to speeds of nearly 400 km/s. Using a combination of gravitational lensing and stellar kinematics, scientists measured its mass with remarkable precision, despite the extreme distance.

Its sheer size places it near the theoretical upper limit for black holes formed through known processes, likely the product of countless galaxy and black hole mergers over cosmic time. Now dormant, it may represent the quiet final stage of a long evolutionary journey a titanic remnant lurking at the very edge of astrophysical possibility.

Credit: Carlos R Melo-Carneiro et al., MNRAS 541 (4): 2853–2871 (2025).

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