Astronomers have discovered that the well-studied binary star system V404 in the constellation Cygnus actually contains three objects – an invisible black hole and two stars orbiting it at vastly different distances.
This discovery indicates the possibility of long-term coexistence of Bs with stars, reported the press service of the Massachusetts Institute of Technology (MIT).
“Previously, we have never been able to calculate the age and determine the formation history of long-existing black holes. The discovery of three objects at once in the star system V404 allowed us to determine the age of the black hole present in it – about four billion years , and also to understand that it arose as a result of a complete gravitational collapse of another star,” explained MIT researcher Kevin Barge, whose words were quoted by the university’s press service.
As the scientists explain, the star system V404 was previously considered to be one of the closest to Earth microquasars – double stars in which there is a black hole and an ordinary star. They are located at a relatively close distance from each other, which is why the black hole constantly “pulls” the matter of the star towards itself, absorbs part of it and throws out the rest in the form of plasma beams accelerated to speeds close to light.
Recently, scientists noticed that at a very short distance from V404 there is another star that moves around the center of the Galaxy at exactly the same speed as the microquasar itself. This coincidence forced scientists to track the movement of these objects using the ground-based VLT telescope, as well as to analyze archival images.
Examination of these images indicated that the detected star was part of the V404 system. It is located 3.5 thousand astronomical units (the average distance between the Earth and the Sun) from the black hole and the other star, and it is comparable in mass, age and size to the Sun. This discovery is a big surprise for scientists, as it shows an unexpectedly large age of the black hole – about four billion years – and an exotic scenario for its formation.
The supernova explosion that accompanies the transformation of large stars into black holes should have generated a shock wave that would have ejected the star discovered by the astronomers into outer space. This did not happen, which is why scientists believe that this black hole arose in the early stages of the formation of the V404 star system as a result of a direct and complete gravitational collapse of one of the stars, which was not accompanied by a supernova explosion.
Theoretical calculations carried out by astronomers speak in favor of this hypothesis and show that over the next billion years the black hole attracted almost half the mass of its neighboring star to itself, as a result of which it became half the size of a distant one. newly discovered star. This shows that black holes can coexist next to stars for a very long time, even inside microquasars, the scientists conclude.
