The latest study by scientists reveals how our solar solar system may have formed in the wind-blown bubbles around a giant, long-dead star, which is more than 40 to 50 times the size of our own Sun. Although there are many impressive and interesting discoveries that the humans have made about the universe, the scientists are still unsure about the birth story of our solar system.
The general prevailing theory is that our solar system formed billions of years ago near a supernova. But, the new scenario instead begins with a giant type of star called a Wolf-Rayet star. The Wolf-Rayet stars are very hot and expel their outer layers in the form of gas at extremely high velocities. So when such a star sheds its mass, the stellar wind plows through the material that was around it, forming a bubble structure with a dense shell, called as the Wolf-Rayet Bubble.
Nicolas Dauphas, professor at University of Chicago in the US said, “The shell of such a bubble is a good place to produce stars because dust and gas become trapped inside where they can condense into stars.”
According to the study published in the Astrophysical Journal, one per cent to 16 per cent of all Sun-like stars could be formed in such stellar nurseries. This setup differs from the supernova hypothesis in order to make sense of two isotopes that occur in strange proportions in the early solar system, compared to the rest of the galaxy.
Meteorites left over from the early solar system tell us there was a lot of aluminium-26. In addition, studies, including a 2015 one by Dauphas and a former student, increasingly suggest we had less of the isotope iron-60. This brings scientists up short, because supernovae produce both isotopes.
Vikram Dwarkadas, a research associate professor at University of Chicago and lead author of the study said, “It begs the question of why one was injected into the solar system and the other was not.” This brought them to Wolf-Rayet stars, which releases lots of aluminium-26, but no iron-60.
Eventually, part of the shell collapses inward due to gravity which then formed into our solar system. The life of the giant Wolf-Rayet star that sheltered us ended long ago, likely in a supernova explosion or a direct collapse to a black hole.