Astronomers See ‘Best Evidence Yet’ of a Black Hole in the Milky Way

German astronomers said Wednesday they had all but proved there is a massive black hole at the center of our galaxy, the Milky Way. Reinhard Genzel of the Max Planck Institute for Extra-Terrestrial Physics, near Munich, said he remained cautious about claiming absolute proof, but “it was caution backed up by the best evidence that has yet existed,� he said.

The only means of detecting a black hole is by observing its gravitational effects on other objects. Since 1992, scientists at the institute have measured the “proper� motions of 39 stars in the Milky Way at right angles to line-of-sight velocities, they report in the Oct. 3 issue of Nature. Their observations support the assumption that the stars moved in circular orbits around a large central mass with gravitational pull.