Fastest-known star zooms under Milky Way black hole's influence

Scientists have discovered the fastest-known star, named S301, which orbits the supermassive black hole at the center of our galaxy, Sagittarius A* (Sgr A*). This stellar speedster travels at speeds up to approximately 56 million miles (90 million kilometers) per hour, more than 8% the speed of light. No other star in our galaxy or beyond has ever been recorded at such a speed.

The star, around 50% more massive and five times brighter than our sun, takes about 8.7 years to complete an elliptical orbit around Sgr A*, passing as close as 11.5 times Earth's orbital distance from the sun and as far as 1,360 astronomical units away. Black holes, like Sgr A*, are extremely dense with gravity so strong that not even light can escape.

With Sgr A* possessing about 4 million times the sun's mass, S301 should remain safe from the black hole's gravitational pull, as its orbit is not expected to decay soon. The researchers believe that observing the star's orbit may provide insights into the black hole's spin, which is currently unknown. By studying how S301's orbit changes as it passes close to Sgr A* every 8.7 years, scientists may be able to directly determine the black hole's spin within the next decade.