Astronomers using the GRAVITY instrument on the Very Large Telescope have discovered a star designated S301 that passes closer to Sgr A* than any previously known star. The star moves at 8% the speed of light and completes an orbit in just 8.7 years, making it the fastest-orbiting star observed near the Milky Way's central black hole.

The extreme eccentricity of S301's orbit, measured at 0.9832, means it traces a highly squashed path that brings it extremely close to Sgr A* before swinging far away. This close approach allows scientists to study how the black hole's spin affects stellar motion, as the spin influences orbital precession.

The discovery comes from observations conducted since 2017 using the GRAVITY instrument, which combines light from four telescopes to achieve the resolution of a single 130-meter telescope. By analyzing the star's orbit, researchers can better understand the properties of Sgr A* and test Einstein's theory of general relativity in extreme gravitational fields.

This finding represents a significant breakthrough in black hole research, providing new opportunities to measure the spin rate of our galaxy's central black hole and study the effects of intense gravity on nearby matter.