One of the closest to the Earth black hole V404 Cygni was twice closer than previously thought - it is located at a distance of 7.8 thousand light years . These data were obtained during the study, whose results are published in The Astrophysical Journal.

Thus, V404 Cygni is located close enough to the Earth, although, for comparison, the nearest star to our planet - from Proxima Centauri star system Alpha Centauri - removed 4.2 light-years. Because black holes closest to our planet - 1,600 light years - the facility is located V4641.

Black holes, scientists call objects which the gravitational pull is so great that they "do not let go" from itself, even radiation. For this reason, observe the black hole itself is impossible. Their presence, scientists judged, in particular, the emission of the accretion disk - material that falls into the hole.

Authors of new work seen as shifting the position of V404 Cygni in the sky as the Earth's rotation around the sun. This technology is called parallax. It is used to determine the location of remote objects. The researchers worked with a system of radio telescopes High Sensitivity Array. In earlier studies we used less sensitive instruments, causing scientists to underestimate the impact on the observation dust that fills the space.

According to the researchers, the new estimate of the distance to V404 Cygni will help in the study of the evolution of black holes. These objects can be formed by the collapse of stars, do not turn into supernovae. In addition, the birth of a black hole can be preceded by a supernova explosion. In the latter case, a black hole is formed to move at high speed.

Recently, another group of astronomers has made a very important for the study of black holes opening. Scientists have found an intermediate link between a black hole and a white dwarf. Discovered by researchers object is formed in the case, "the parent star is too small to become a black hole or neutron star, but too large to turn into a white dwarf.