According to some theories, the emergence of the Solar system was provoked closest supernova explosion or impact stars AUG. Although the issue of creation of our star and its planetary system is still far from a final decision, but a number of intriguing conjecture suggests that not only the gravitational force led their birth.

The suddenness of the beginning of the formation of our luminary 4,59 billion years ago implies incentive podeystvovalo so that matter is thickened and formed a newborn star. Such an incentive could be a supernova explosion near enough from the gas-dust nebulae in which it was born. Such stars of the second generation during the explosive transformation implement dreams alchemist - produce heavy elements, gold, platinum, and transuranium elements. Our planet Earth and the asteroid chemical composition correspond to this assumption.

The alternative is the impact again nearest star of another type, is not explosive as supernovas, and belonging to the asymptotic giant branch (AUG) on the chart, Hertzsprung-responsible. By the way, the Sun in its stellar evolution, too, will become a red giant through billions of years! Such giants have a powerful stellar winds - they exude a plasma with great speed and intensity that has a strong influence on surrounding material environment.

Scientists Alan Boss (Boss Alan) and Sandra Keiser (Sandra Keiser), astronomers at the Carnegie Institution (Washington, USA), has tried to solve the problem, carrying out model calculations of the distribution of matter made by the supernova explosion or powerful stellar wind of the red giant in the area of occurrence of the future of the Solar system. The astrophysicists know that certain radioactive isotopes of substances generated by the supernova stars and red giants were significant differences in concentrations from those available in our Solar system. First of all, it isotope of iron-60, for which half-life equal to 2.6 million years, and the products of its decay.

So, we are interested isotope of iron-60 occurs only in thermonuclear synthesis in significant quantities. And supernova stars, and the stars AUG able to raise him, but the simulation showed that the advantage for the supernova, because of the shock front AUG-stars too slow and massive in comparison with the shock wave from the explosion of the first. The shock wave of the red giant would iron-60 only on the periphery of the protoplanetary cloud, but could not get into his midst.

But, according to research, the distribution of iron-60 in the centre of the protoplanetary cloud (and later, as I suppose, and on Earth) coincides with the distribution of this isotope in meteorites. The calculations show that the blast wave threw directed to the center of the system of local streams, penetrated to the center of the system in such a way that formed the uneven presence of some heavy elements on planetary bodies that today revolve around the Sun. The model showed that after exposure to the stimulus collapse of gas-dust nebula began only after 100 thousand years when there is a protostar, which later set up the Sun.

The authors of all these constructions adhere to the view (you will learn by reading the publication in Astrophysical Journal Letters, and the announcement article is proposed here)that supernova was the impetus of generation of the Solar system, not the star of the asymptotic series of the giants, the impact of which could not have such selectivity in "load isotopes" planets and small bodies of the Solar system.

If you remember gravitational simulation of the evolution of stars like the Sun, it previously seemed extremely simple: a purely gravitational compression could cause the Sun from the protoplanetary nebula in thousands of years, and planets, and without any additional stimulation external processes. However, the presence in the Solar system abnormally high amount of gold and uranium leads to the necessity of attracting relatives of supernova explosions, is able to provide this feature isotopic composition. And the time of formation of protostars, estimated at 0.1 million years, may seem too slow.

Tatiana Valchuk