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2018-03-23

The binary star concept Part 2

It is interesting that there is still almost the same lines, but with a large offset. It is the inner layers surpass the outer. The high Shine visible radiation line heavier than hydrogen, the ionized elements. This means that expanded through the atmosphere shines through the surface of the hot core.

Then the absorption line of the atmosphere is weaker, and there are lines of radiation characteristic of nebulae, but weaken and they are: the nebula dissipated.

The so called, Late in a close binary at the end of a complex evolution turn into a super dense bodies (white dwarfs, neutron stars or black gifts). The study of such stars is of particular interest to modern scientists, not just astrophysicists.

Consider one of the existing scripts. The pair consists of stars of greater mass (B) and stars with a smaller mass (M). Both normal star, in the nuclei undergoing fusion reactions convert hydrogen into helium.

Star B faster, so the core turns into helium, and the atmosphere expands and fills the Roche lobe of a star B.

The star M flows approximately 70 percent of the mass of star B, so M turns into a hot supergiant.

Having lost so much weight, B is a star of type wolf Rayet. Spectrum of these stars looks very strange. Wide bandwidth radiation of high potentials excitation – a result of the fact that the surface of the hot nucleus at great speed and pulled streams of ionized gases: oxygen, nitrogen, carbon. And at the same time, in the spectrum there are signs of a cold gas bloated surface layers of the atmosphere.

If a sufficiently large masses, its helium core continues the fusion reaction with the formation of all the heavier chemical elements up to iron. Then B explodes as a supernova relatively small luminosity, because she is a star without an atmosphere, but, like all supernovas, remains a neutron star or a black hole.

Star M the time expanded and filled its Roche lobe, its atmosphere began to flow on a small rapidly rotating compact object remaining after the explosion of a supernova.

Falling as the funnel, and forming an accretion disk, the matter of the star is heated by friction to such an extent that the object B is transformed into a vibrant source x-ray pulsar, a pulsar or a black hole. From pulsars where the magnetic field reaches (10^12) HS, out jets with velocities close to the speed of light. X-ray sources are observed only from space, and radio pulsars can be observed from Earth.

Losing weight, object M can also become a star of wolf Rayet and to repeat the fate of star B. at the same time a dual system loses a large share of the mass in the form of a gas nebula, enveloping both stars, and the stars, losing mass and energy, moving closer, trying to fall on the center of mass. The periods of orbital revolution are measured only and minutes. Drop prevents increasing orbital speed.

The nebula gradually dissipated. This system, combining neutron stars and/or black holes is of great interest, including as a source of powerful gravitational waves. Gravitational waves arise when moving with variable acceleration of objects of all masses (one mechanism). But in terrestrial conditions, the emerging gravitational waves is so weak that observations, so the researchers turned to the cosmic bodies.

The achievement of exceptional importance occurred, when for the first time on Earth was recorded gravitational waves. The source turned out to be a double star, consisting of two black holes. Their masses were 29 and 36 solar masses. They spun around a common center of mass. Losing energy by gravitational, they revolved faster and faster, getting closer to each other.

The period of revolution around the center of mass were becoming shorter, the interaction is stronger, the amplitude of gravitational waves all the more.

Abruptly the flux of gravitational waves has ceased, since both bodies merged into one. His weight was only 62 solar masses and 3 solar masses has turned into the energy of gravitational waves.

The power flux of gravitational waves you can imagine, knowing that the waves propagate in all directions, and reached us just one “ray”. At the speed of light he reached the Ground just after 1 300 000 000 years. However, the signal was already very weak, and accept it was worth a lot of effort.

And yet, 14 Sep 2015 two detectors the American LIGO complex independently of each recorded signal.

An even weaker signal from the other pair of United swashplate stars was adopted on 26 December 2015.

The LIGO system is improved, and the construction of new receivers of gravitational waves in China, Europe and Japan – it’s only the beginning.

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