I looked it up! "Given a recent estimate of 4.3 million solar masses for the mass of Sagittarius A* and S2's close approach, this makes S2 the fast

I looked it up! "Given a recent estimate of 4.3 million solar masses for the mass of Sagittarius A* and S2's close approach, this makes S2 the fastest known ballistic orbit, reaching speeds exceeding 5000 km/s (11,000,000 mph) or 1.67~% of the speed of light and acceleration of about 1.5 m/s2 or almost one-sixth of Earth's surface gravity.[7]" https://en.wikipedia.org/wiki/S2_%28star%29 https://en.wikipedia.org/wiki/S2_%28star%29 Edit: wait that's not it, that's S0-2, but you're talking about S14/S0-16: https://en.wikipedia.org/wiki/Sagittarius_A*#Central_black_hole https://en.wikipedia.org/wiki/Sagittarius_A*#Central_black_h... From those parameters, its perihelion speed would be about 8,200 km/s (2.7% c), using the classical approximation. https://en.wikipedia.org/wiki/Perihelion#Mathematical_formulae https://en.wikipedia.org/wiki/Perihelion#Mathematical_formul...