The Near Earth Black Holes

Washington DC - An international team of astronomers have accurately measured the distance from the earth into a black hole for the first time. No need to race with a mathematical model of astronomers came up with a distance of 7800 light-years away, much closer than expected today. The researchers achieved this breakthrough by measuring the radio emission from black hole with a cluster of stars that are fading into the disappeared.

Because the margin of error is much lower (6%), astronomers can now get a better picture of how black holes evolve. In addition, the proper distance is important to measure the velocity of a black hole.

Astronomical distance of the most easily measured by using the so-called paralak trigonometrs, in which astronomers take advantage of the annual shift of star positions as a consequence of Earth's orbit around the sun (parallax shift). Peter Jonker of the SRON Netherlands Institute for Space Research and her colleagues have now applied this method for the first time in the relatively near a black hole and associated star clusters, V404 Cygni, in the constellation Cygnus. Outer layers of the star being drawn into a black hole. This gas is first accumulated in the plasma disk around a black hole before it disappeared into it, a process in which many X-rays and radio waves emitted.

Jonker and his colleagues can accurately measure the parallax shift of the binary system uses a combination of telescopes scattered across the globe, An array with high sensitivity. By using this approach, the astronomers could determine that the black hole V404 Cygni is 7800 light years from Earth, slightly more than half the distance previously estimated. The researchers believe that the assessment is too high from distance earlier this is due to a too low estimate of the absorption and diffraction of interstellar dust that can provide a margin of error of about 50 percent. Moreover a new measurement error margin of less than 6 percent.
Supernova

From these measurements the researchers to know that black holes evolved from a supernova explosion, and that moves through space at a rate of about 40 km per second. Binary star system has been picking up speed during the explosion. Jonker commented: "With this information, we have gained a better idea of ​​how black holes evolve again. For example, we hope to answer the question about whether there is a difference between a black hole which evolved directly from the collapse of a star without supernovae and black holes which evolved through the supernova and star intermediaries while, a proto-neutron star. We hope that the black hole in the last group can get a hit. Black holes are formed in this way can move through space faster ".

Interestingly, V404 Cygni belong to this second group but have not received a 'big blow

Researcher James Miller-Jones added: "We are now trying to apply the same method of measurement for some black hole."