Famous effect of general relativity provides accurate mass of distant white dwarf
F.W. Dyson, A.S. Eddington, C. Davidson
For the first time, astronomers have seen a star outside of the solar system bend the light from another star. The measurement, reported June 7 in Austin, Texas, at a meeting of the American Astronomical Society, vindicates both Einstein’s most famous theory and what goes on in the inner lives of stellar corpses.
Astronomers using the Hubble Space Telescope watched as a white dwarf passed in front of a more distant star. That star seemed to move in a small loop, its apparent position deflected by the white dwarf’s gravity.
More than a century ago, Albert Einstein predicted that the way spacetime bends around a massive object — the sun, say — should shift the apparent position of stars that appear behind that object. The measurement of this effect during a solar eclipse in 1919 confirmed Einstein’s general theory of relativity: Mass warps spacetime and bends the path of light rays (