Researchers have discovered that ancient stars can produce elements with atomic masses of more than 260, heavier than those found naturally on Earth. This discovery improves our understanding of element formation in stars, particularly through the rapid neutron capture processes (r-processes) that occur in neutron stars. . Credit: SciTechDaily.com
A new study reveals that ancient stars can produce elements heavier than Earth, with atomic masses of more than 260, advancing our understanding of cosmic element formation.
How much do elements weigh? An international team of researchers has found that ancient stars had the ability to produce elements with an atomic mass of more than 260, heavier than any element on the periodic table that occurs naturally on Earth. I discovered that. This discovery deepens our understanding of element formation in stars.
space element factory
We are literally made of star stuff. Stars are elemental factories, where elements are constantly merging or breaking down to create other lighter or heavier elements. When we refer to light or heavy elements, we are talking about their atomic mass. Roughly speaking, atomic mass is based on the number of protons and neutrons in the nucleus. atom of its elements.
The heaviest elements are only known to be produced in neutron stars by rapid neutron capture processes, or r processes. Imagine a single atomic nucleus floating in a soup of neutrons. Suddenly, a bunch of these neutrons attach themselves to the nucleus in a very short time (usually less than a second), causing a change from neutrons to protons inside, and voila! Heavy elements such as gold, platinum, and uranium are formed.
Instability of heavy elements
The heaviest elements are unstable or radioactive and decay over time. One way to do this is through a split called fission.
“If you want to make heavier elements, such as lead or bismuth, you need the R process,” says Ian Roederer, associate professor of physics. north carolina state university and lead author of the study. Mr. Roederer previously attended the University of Michigan.
“We need to add a lot of neutrons very quickly, and the problem is that we need a lot of energy and a lot of neutrons to do that,” Roederer says. “And the best place to find both is at the moment of a person’s birth or death. neutron staror when neutron stars collide and the raw materials for the process are produced.
“We have a general understanding of how the r process works, but the conditions of the process are very extreme,” Roederer says. “We don’t really know how many different sites in the universe generate r-processes, and we don’t know how r-processes end. We also don’t know how many neutrons there are Can you add more? Or how heavy can the elements be? So we looked at the elements produced by nuclear fission in well-studied old stars to find out how heavy these elements are. We decided to see if we could answer some of the questions.”
Identify previously unrecognized patterns
The research team newly investigated the abundance of heavy elements in 42 well-studied stars. milky way. These stars were known to contain heavy elements formed by the r process in earlier generations of stars. By looking more broadly at the amounts of each heavy element found in these stars, rather than individually, as is more common, they identified previously unrecognized patterns.
These patterns indicated that some elements listed near the middle of the periodic table, such as silver and rhodium, were likely remnants of nuclear fission of heavy elements. The research team was able to confirm that the r process can produce atoms with an atomic mass of at least 260 before fission.
“That 260 is interesting because, even in nuclear weapons tests, nothing that heavy has ever been detected in space or in nature on Earth,” Roederer said. “But observing them in space gives us guidance on how to think about models and fission. It also gives us insight into how the rich diversity of elements came about.” may be given.”
For more information on this research, see ‘Incredibly profound’ evidence for nuclear fission throughout the universe.’
Reference: “Elemental abundance patterns in stars show splitting of nuclei heavier than uranium” Ian U. Roederer, Nicole Vassh, Erika M. Holmbeck, Matthew R. Mumpower, Rebecca Surman, John J. Cowan, Timothy C. Beers, Rana Ezzeddine, Anna Froebel, Therese T. Hansen, Vinicius M. Placko, Charlie M. Sakari, December 7, 2023. science.
DOI: 10.1126/science.adf1341
The research was published in the journal Science and was supported in part by the National Science Foundation and the National Aeronautics and Space Administration.
Source: scitechdaily.com
