Number 232 (Story #2), July 6, 1995 by Phillip F. Schewe and Ben Stein GRAVITATIONALLY REDSHIFTED LIGHT suggests the existence of a black hole in the active galaxy MCG-6-30-15. According to theories of black holes, matter drawn in toward a black hole should accelerate to high speeds. Providing the matter has not yet crossed the point- of-no-return known as the Schwarzschild radius, radiation emitted by the matter can still escape from the vicinity, albeit in an altered form. Just such a relativistic gravitational-redshift effect has now been observed by astronomers using the ASCA x-ray satellite. The spectrum of ionized iron atoms tells the story: from the broadening and asymmetry of specific emission lines, the ASCA scientists deduce that the luminous matter in question was traveling at a velocity of 100,000 km/sec and was at a distance of only about 3-10 Schwarzschild radii from the center of what is probably a supermassive black hole. (Y. Tanaka et al., Nature, 22 June 1995.)