In the constellation Telescopium, a black hole is hidden in a binary galaxy (v723mon) visible to the naked eye. That is the closest known black hole to Earth. 1500 light-years may seem big to us, but in terms of the size of the universe, it’s like a neighboring house. It is the smallest known today. It is only three times the mass of the Sun.It does not emit any radiation, but it can clearly see the black hole, the star, and the red giant. (Tidal distortion). Just as our moon stretches the ocean. Knowing that there is a black hole in an array that we can see with our own eyes makes everyone excited.