Spinstars may be the first polluters of the universe

April 28th, 2011 - 6:53 pm ICT by ANI  

Washington, April 28 (ANI): A new study has found that spinstars, the first generations of massive stars, may be the first polluters of our Universe.

An international team of astronomers led by Cristina Chiappini from the Leibniz-Institut fuer Astrophysik Potsdam (AIP) and the Instituto Nazionale di Astrofisica (INAF) came to the conclusion after analysing chemical composition of some of the oldest stars in our galaxy.

“We think that the first generations of massive stars were very fast rotators — that’s why we called them spinstars”, said Chiappini.

Massive stars live fast and furious, and hence the first generations of massive stars in the Universe are already dead.

However, their chemical imprints, like fingerprints, can still be found today in the oldest stars in our galaxy. These fossil records are thus the witnesses of the nature of the first stellar generations to pollute our Universe.

Soon after the Big Bang, the composition of the Universe was much simpler than at present as it was made of essentially only hydrogen and helium.

The chemical enrichment of the Universe with other elements had to wait around 300 million years until the fireworks started with the death of the first generations of massive stars, polluting the primordial gas with new chemical elements, which were later incorporated in the next generations of stars.

Using data from ESO’s Very Large Telescope (VLT), the astronomers reanalysed spectra of a group of very old stars in the Galactic Bulge.

These stars are so old that only very massive, short-living stars with masses larger than around ten times the mass of our Sun should have had time to die and to pollute the gas from which these fossil records then formed.

As expected, the chemical composition of the observed stars showed elements typical for enrichment by massive stars.

The findings will be published in Nature. (ANI)

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