Astronomers Mark Black Hole Anniversary GREEN BANK, W.Va. -- Astronomers gathered this week to mark the 30th anniversary of the discovery here of the radio signature of what is believed to be the super-massive black hole at the center of the Milky Way.How many standard candles this black hole deserves was not mentioned. Posted by Vanderleun at April 5, 2004 5:54 PM | TrackBackRobert L. Brown and Bruce Balick discovered Sagittarius A, a black hole with three million times the mass of the sun at a distance of 24,000 light years, and attended a symposium at the Green Bank National Observatory on new center-galaxy research. The event drew 50 radio, X-ray and infrared astronomers and scientific historians from around the world.
