The
gold in your jewelry and the uranium powering nuclear reactors might seem
entirely unrelated. However, in a paper published in Nature, two astrophysicists suggest that many of the heavy elements
found throughout the universe are created as a result of a collapsar, a rare
kind of supernova.
Collapsars
occur when a rapidly-rotating, high-mass star collapses into a black hole,
causing the outer layers to explode in a supernova. As the star dies, its core
undergoes a catastrophic gravitational collapse resulting in the formation of a
black hole, leading to the supernova explosion of the outer shell. Then, the
remnants of the star fall into orbit around the black hole, creating a vortex
of high-energy lighter elements. In this extreme scenario, the conditions are right
enough to allow a nuclear process known as the r-process take place, causing
many of the heavy elements of the universe to form.
It was previously
thought that the majority of elements formed via the r-process were a result of
neutron star mergers. Nonetheless, a recent analysis of the galactic abundance
of one of these r-process elements, europium, seems to indicate that a
different mechanism was supplying the universe with the multitude of heavy
elements we see today.
The authors
of this study identify collapsars as a likely source. In fact, over 80% of
r-process elements could be formed via collapsar-catalyzed nuclear reactions. Although
collapsars are much rarer than neutron star mergers, they produce a much
greater quantity of these r-process elements, explaining why they create the majority of heavy elements
in the universe.
Read
the official research paper here:
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