Milky Way's Core Black Hole Sent Out Massive Flares 300 years ago

Our galaxy’s central black hole let loose a powerful flare three centuries ago.
The finding helped resolve a long-standing mystery: why is the Milky Way’s black hole so quiescent? The black hole, known as Sagittarius A-star (A*), is a certified monster, containing about 4 million times the mass of our Sun. Yet the energy radiated from its surroundings is thousands of millions of times weaker than the radiation emitted from central black holes in other galaxies.
"We have wondered why the Milky Way’s black hole appears to be a slumbering giant," says team leader Tatsuya Inui of Kyoto University in Japan. "But now we realize that the black hole was far more active in the past. Perhaps it’s just resting after a major outburst."
http://www.dailygalaxy.com/my_weblog/2008/08/milky-ways-gian.html