Now, a big bubble theory 

Now, a big bubble theory 

Context

Scientists have said that the solar system could have formed in the bubbles produced by a giant, long-dead star, which was 40 to 50 times the size of the sun

No consensus

Despite the many impressive discoveries humans have made about the universe, scientists are yet to come to a consensus about the birth story of the solar system

Present theory

The prevailing theory is that the solar system formed billions of years ago near a supernova but the new scenario, explained in a paper in the Astrophysical Journal, begins with a giant type of star called a Wolf-Rayet star

Wolf Rayet star

• They burn the hottest of all stars, producing tonnes of elements which are flung off the surface in an intense stellar wind.
• As the Wolf-Rayet star sheds its mass, the stellar wind ploughs through the material around it, forming a bubble structure with a dense shell
• 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
  • The researchers estimate that 1% to 16% of all sun-like stars could be formed in such stellar nurseries.

Presence of two elements

The study addresses a cosmic mystery about the presence of two elements in our solar system compared to the rest of the galaxy.

• Meteorites left over from the early solar system suggests there was a lot of aluminium-26. In addition, studies increasingly suggest the solar system had less of the isotope iron-60.
• This brings scientists up short, because supernovae produce both isotopes.
• It begs the question of why one was injected into the solar system and the other was not. This brought the scientists to Wolf-Rayet stars, which release lots of aluminium-26, but no iron-60