'As light travels close to a rotating black hole, the rotation of spacetime causes the light's path to be curved or twisted,' Calmet said.

This frame dragging also gives rise to weird visual effects around black holes. This phenomenon, called 'frame dragging' or the 'Lensing-Thirring effect,' means that to understand the way space around a black hole behaves, researchers need to know its spin. That means that when they spin, black holes literally twist up the very fabric of space-time and drag anything within the ergosphere along. This effect is unique to black holes and does not occur with solid bodies like planets or stars.' 'Due to the extreme gravitational forces near a black hole, the rotation causes spacetime to become highly curved and twisted, forming what is known as the ergosphere.

'While the rotation of a planet or star is governed by the distribution of its mass, the rotation of a black hole is described by its angular momentum,' Calmet said. Whereas planets, stars and asteroids are solid bodies with physical surfaces, black holes are actually regions of space-time bounded by an outer nonphysical surface called the event horizon, beyond which no light can escape. 'Discovering that Sgr A* is rotating at its maximum speed has far-reaching implications for our understanding of black hole formation and the astrophysical processes associated with these fascinating cosmic objects,' Xavier Calmet, a theoretical physicist at the University of Sussex who was not involved in the research, told Live Science in an email.Ī black hole's spin is different from those of other cosmic objects.

21 in the journal Monthly Notices of the Royal Astronomical Society. The team described Sgr A*'s blistering speed in a study published Oct. Daly, a physicist at Penn State, and colleagues found that the rotational speed of Sgr A* is between 0.84 and 0.96 - close to the top limit defined by a black hole's width.

The spin speed of a black hole is defined as 'a' and given a value from 0 to 1, with 1 being the maximum rotational speed to a particular black hole, which is a significant fraction of the speed of light. Physicists calculated the rotational speed of the Milky Way's supermassive black hole, called Sagittarius A* (Sgr A*), by using NASA's Chandra X-ray Observatory to view the X-rays and radio waves emanating from outflows of material. The supermassive black hole at the heart of our galaxy isn't just spinning - it's doing so at almost maximum speed, dragging anything near it along for the ride.

Animated gifs of spinning planet earth