S301 star discovered as fastest moving object in the Milky Way

Astronomers have discovered S301, the fastest star ever recorded in the Milky Way. The star travels at approximately 25,000 kilometers per second, which is more than 8 percent of the speed of light.

Using the GRAVITY instrument at the European Southern Observatory’s Very Large Telescope Interferometer (VLTI), researchers identified S301 orbiting Sagittarius A*, the supermassive black hole at the center of our galaxy. The star follows an extremely tight and eccentric orbit, completing a full revolution in just 8.7 years. At its closest approach, it reaches a distance roughly 12 times that of the Earth-Sun gap, comparable to the orbit of Saturn.

This discovery provides a unique natural laboratory for testing Albert Einstein’s theory of general relativity. Because S301 passes so close to the black hole, scientists hope to use its movement to directly measure the spin of Sagittarius A* and observe how the rotating black hole drags and distorts spacetime. This measurement could offer critical confirmation of fundamental physics in extreme environments.