There are different theories about how it may have formed our Solar system. But at the moment scientists have not yet come to a common agreement and a model that could explain all the peculiarities and oddities associated with it. In the Treasury of such theories can be added and the latest work of researchers from the University of Chicago who argue that their model is able to explain the very unusual aspects of the early history of our system.
According to the General common theory, our Solar system formed several billion years ago in the explosion of a supernova, the effects of which started some processes in gas-dust nebula, which later came our Sun.
However, according to new proposed model, it all started thanks to the explosion of a star class wolf — Rayet, which in size was 40-50 times more than our Sun. The stars of this class are considered to be one of the hottest. In addition, it is believed that stars of this class produce a huge number of chemical elements that are ejected from their surfaces via strong stellar winds. As soon as the star wolf-Rayet loses its mass, its stellar wind “stirs” the chemical elements around her, eventually forming a bubble with a dense shell.
Computer model shows how the stellar wind mass transfer from the surface of the giant star and over millions of years to form bubbles around it
“Shell is like a bubble and accumulates beneath the dust and gas provides an ideal environment for the production of new stars,” says study co-author Nicholas Doffs, Professor, Department of geophysical Sciences University of Chicago.
Researchers believe that about one to sixteen percent of all sun-like stars could appear in such “stellar nurseries”.
A new model for the formation of the Solar system is very different from a hypothesis in which the ancestor of our Sun is considered to be the supernova explosion. And yet, she is able to explain one obscure aspect that I can’t explain other theories. Aspect is very important, as it is significantly different from our young system from the rest of our galaxy. Speech in particular goes about the unusual proportions of certain isotopes that existed in our system in its early days: isotope aluminium-26, which was much greater than elsewhere (its presence told us meteorites that have remained since the young Solar system), and isotope iron-60, which was much less, as evidenced by the results of earlier studies carried out in 2015.
This has led scientists to some questions, because supernovae produce the same amount of both isotopes.
“We asked the question: why in our Solar system there is a difference in the amount of these isotopes, if the supernova was supposed to provide them with the same number?”, — shared Vikram Dwarkadas, another study co-author and associate Professor in the Department of astronomy and astrophysics, University of Chicago.
Thus, the researchers eventually came to the stars, wolf — Rayet, which produce much of the isotope aluminum-26, but not iron-60.
“We assume that the isotope aluminum-26 produced the star of the class wolf — Rayet thrown to the outer limits of the bubble on the dust particles that accumulate around the star. These particles have sufficient momentum and was thrown through the shell, but most of them broken on the shell, sealing within it the isotope of aluminium,” says Dwarkadas.
In the end, under the influence of gravity stars part of the shell collapsed, that started the process beginning of formation of our Solar system.
The model slice showing how bubbles around massive stars evolve over millions of years (see clockwise from the top left of the image)
As for the fate of the star wolf — Rayet, for researchers it remains a mystery. Very likely, her life ended in the explosion of a supernova or a direct collapse to a black hole. But in both cases it was about the production of a small amount of the isotope iron-60.