General, Research, Technology

The solar system could form inside a giant cosmic bubble

There are a variety of theories about how she couldto form our solar system. But at the moment, scientists have not yet reached a common agreement and a model that could explain all those features and oddities associated with it. In addition to these theories, we can add the latest work of researchers from the University of Chicago who claim that their model is able to explain very unusual aspects related to the early history of our system.

According to a common widespread theory, ourThe solar system was formed several billion years ago as a result of the explosion of a supernova, the effects of which triggered certain processes in the gas and dust nebula, from which our Sun subsequently emerged.

However, according to the new proposed model, allIt began thanks to the explosion of a Wolf-Rayet-class star, which was 40-50 times larger in size than our current Sun. Stars of this class are considered one of the hottest. In addition, it is believed that stars of this class produce a huge amount of chemical elements that are ejected from their surface with the help of strong stellar winds. As the Wolf-Rayet star loses its mass, its stellar wind “shakes up” the chemical elements around it, eventually forming a bubble with a dense shell.

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A computer model shows how stellar winds transfer mass from the surface of a giant star and form bubbles around it for millions of years.

"The shell of a similar bubble and accumulating underdust and gas are an ideal environment for the production of new stars, ”says co-author of the study Nicholas Doffas, professor of the Department of Geophysical Sciences at the University of Chicago.

Researchers estimate that approximately one to sixteen percent of all sun-like stars could appear in just such a "star nursery".

The new solar system formation model is highlydiffers from the hypothesis in which the supernova explosion is considered the progenitor of our Sun. And yet, it is able to explain one obscure aspect that other theories cannot explain. The aspect is very significant, since it significantly distinguished our young system from the rest of our galaxy. In particular, we are talking about the unusual proportion of some isotopes that existed in our system in its early days: the aluminum-26 isotope, which was much larger than everywhere (we were informed about its presence by meteorites that have remained since the time of the young Solar system), and also the iron-60 isotope, which was much smaller, as evidenced by the results of earlier studies conducted in 2015.

This led scientists to some questions, because supernovae produce the same amount of both isotopes.

“We wondered: why in our solar system there is a difference in the volume of these isotopes, if the supernova should have supplied them with the same amount? ”, said Vikram Dvarkadas, another co-author of the study and associate professor of the Department of Astronomy and Astrophysics at the University of Chicago.

Thus, researchers eventually came to the Wolf-Rayet stars, which produce a lot of aluminum-26 isotope, but not iron-60.

“We assume that the aluminum isotope is 26,produced by a Wolf-Rayet class star was thrown to the outer boundaries of the bubble on dust particles that accumulated around the star. These particles received enough momentum and were ejected through the shell, but most of them broke into the shell, sealing an aluminum isotope inside it, ”says Dvarkadas.

In the end, under the influence of star gravity, part of the shell collapsed, which launched the process of the beginning of the formation of our solar system.

A slice of a model showing how bubbles around massive stars evolve over millions of years (look clockwise from the upper left of the image)

As for the fate of Wolf’s star herself -Paradise, it is still a mystery to researchers. Most likely, her life ended as a result of a supernova explosion or direct collapse into a black hole. But in both cases, it would be about the production of a small amount of the iron-60 isotope.