The mysterious "black hole" that astronomers have suspected, calculated and predicted - but never verified - for the last 10 years may have been found at the center of a distant galaxy called M 87.

At the center of M 87, which lies 65 million light years away in the constellation Virgo, astronomers using the 48-inch telescope at the Kitt Peak National Observatory in Arizona have found a dark object so dense it appears to be 5 billion times the mass of our own sun.

At the same time, astronomers using the 60-inch and the 200inch telescopes at Mt. Palomar in California have found such a glow of excess light at the center of M 87 that it can only be explained by stars that bunch up and stay bunched up because they're tightly bound to some huge mass astronomers think it an invisible black hole.

"If this mass is a black hole it could be as big as the entire solar system," said Peter J. Young of the astronomy department at the California Institute of Technology, where much of the work was done. "If it's that big the black hole itself would weigh something like 100 octillion metric tons."

The term "black hole" was coined in 1968 by Princeton University's Dr. John Wheeler, from the prediction that when a massive star or galaxy exhausts its nuclear fuel it could collapse suddenly and completely to an object so densely and tightly packed its gravity would allow none of its light to escape.

So dark and dense would it be that a black hole the size of a sugar cube would weigh 1 billion tons. A black hole a mile across in width would have the same mass as our sun does.

In their use of the two big telescopes on Mt. Palomar, astronomers found a "spot" of light at the center of M 87 that could not be accounted for by starlight. Cal Tech's Young said calculations of this "excess" light show it is the equivalent of the light of 100 million suns.

The informed speculation of astronomers is that this excess light is the energy produced when gas, dust and individual star are sucked into a black hole at enormous speeds by its huge gravitational pull. This generates such high temperatures that the heating alone gives off the light equivalent of numerous suns.

The telescope at Kitt Peak was used to measure how fast the stars at the center of M 87 were moving about. These measurements tell astronomers how much mass there is at the galactic center since they can calculate from the speeds of the moving stars how much mass is needed to keep the stars from whirling out of the center of the galaxy.

From their calculations, astronomers estimate there are the equivalent of 60 invisible suns at the center of M 87 for every sun they see. That suggests a black hole so massive that it could cover the entire center of the M 87 galaxy, which itself is 100 times bigger than the Milky Way.