V4641 Sgr: The Closest Black Hole Candidate . ... VLA , NRAO Explanation: An object many astronomers believe is a black hole has been found only 1500 light-years from Earth, making it the closest black hole candidate . Although dramatic explosions emanate from the object, it is far enough away so that we are in no danger. ... V4641 is the fourth known microquasar , a miniature version of the massive, matter spewing black holes thought to exist in the centers of galaxies . ...