M87 black hole rotates at 80% max speed, nears cosmic speed threshold, feeds at 23% light speed

Looking into the heart of galaxy M87 feels like staring into a cosmic engine. A black hole, unimaginably large and powerful, sits at its centre, spinning at furious speed. Now, new analysis of the Event Horizon Telescope (EHT) image reveals just how extreme this giant really is.

Spinning close to universal limits
The black hole weighs about 6.5 billion solar masses. Scientists now believe it spins at around 80% of the maximum speed nature allows. Its inner accretion disc races at 14% the speed of light, nearly 42 million metres per second. The spin calculation came from a closer look at the black hole’s "bright spot"—a key feature in the EHT image.

This uneven glow is due to a phenomenon known as relativistic Doppler beaming. As material circles the black hole, matter on the near side moves toward Earth. That side appears brighter because of its speed, while the far side dims. The contrast allowed researchers to measure rotation more precisely.

Feeding patterns and jet power aligned
The team also analysed the black hole’s magnetic fields. These swirling patterns showed how matter spirals inward. From this, scientists calculated that material falls into the black hole at roughly 70 million metres per second—about 23% of the speed of light.