`SEEMINGLY conclusive evidence'' for a black hole in the galaxy M87 was released yesterday by the Space Science Telescope Institute in Baltimore. For the first time, astronomers have a clear image of a black hole's telltale signature. It is a fast-rotating disc of dust and gas caught in the powerful gravity of an object that has the mass of three billion suns packed into a volume no larger than our solar system.
After repairs last December, the now-sharp-eyed Hubble Space Telescope is providing such images, which astronomers call ``quite spectacular'' and ``totally unexpected.'' Last Thursday, images of remnants of the star that exploded as a supernova seven years ago in the Large Magellanic Cloud were released. Chris Burrows, a European Space Agency astronomer with the institute, said: ``We have never seen anything behave like this before.''
However, it is the black hole that now takes center stage in the Hubble telescope show. A black hole is an object that has condensed under its own gravity to such a density that the gravitational field in its vicinity is too strong for anything - including light - to escape. However, energy is released from material sucked into the hole, just as falling water gives up energy in a hydroelectric dam. Einstein's general theory of relativity provides a theoretical explanation for black holes.
Black holes have seemed the best candidates for the energy sources behind the powerful emissions of light, radio noise, and other radiation from so-called active galaxies and other highly energetic objects. Dust and gas spiraling into a black hole would give up immense amounts of gravitational energy to produce the radiations from an active galaxy such as M87, which is 50 million light years from Earth in the constellation Virgo.