The bending angle is about 100 times smaller than the angular resolution of Hubble, so the two distorted images of the background star cannot be separated, even in high-resolution Hubble images. The black hole's gravity acts like a powerful lens, bending the light of a background star so that it appears as two separate images when the black hole slowly drifts in front of it.

The findings also suggest that stellar-mass black holes do not require some sort of interaction in a double-star system to form but may also be produced in the collapse of isolated massive stars, as has long been proposed by stellar theorists. Bennett presented his team's results today in Atlanta at the 195th meeting of the American Astronomical Society. 'These results suggest that black holes are common and that many massive but normal stars may end their lives as black holes instead of neutron stars,' said David Bennett of the University of Notre Dame, South Bend, Ind. The two isolated black holes were detected indirectly by the way their extreme gravity bends the light of a more distant star behind them. Two international teams of astronomers using NASA's Hubble Space Telescope and ground-based telescopes in Australia and Chile have discovered the first examples of isolated stellar-mass black holes adrift among the stars in our galaxy.ДЄll previously known stellar black holes have been found in orbit around normal stars, with their presence determined by their effect on the companion star. The findings also suggest that stellar-mass black holes do not require some sort of interaction in a double-star system to form but may be produced in the collapse of isolated, massive stars, as has long been proposed by stellar theorists. These new results suggest that black holes are common and that many massive but normal stars may end their lives as black holes instead of neutron stars, the crushed cores of massive stars that end their lives in supernova explosions. Astronomers determined the presence of those compact powerhouses by examining their effect on their companion star. All previously known 'stellar' black holes have been found orbiting normal stars. They detected two of these lonely, invisible objects indirectly by measuring how their extreme gravity bends the light of a more distant star behind them. Astronomers using the Hubble telescope and ground-based observatories have discovered the first examples of isolated, stellar-mass black holes adrift among the stars in our Milky Way Galaxy.

After time adrift among open stars