r-process tagged posts

Gold cannot form until certain unstable atomic nuclei break apart. Exactly how those nuclear transformations unfold has long been difficult to determine. Now, nuclear physicists at the University of Tennessee (UT) report three discoveries in a single study that clarify important parts of this process. Their findings could help researchers build improved models of the stellar events that create heavy elements and better predict the behavior of exotic atomic nuclei.

Heavy elements such as gold and platinum are forged under extraordinary conditions, including when stars collapse, explode, or collide. These events trigger the rapid neutron capture process (or r-process for short). During this process, an atomic nucleus absorbs neutrons in rapid succession...

In our sun’s neighborhood of the Milky Way Galaxy is a relatively bright star, and in it, astronomers have been able to identify the widest range of elements in a star beyond our solar system yet.

The study, led by University of Michigan astronomer Ian Roederer, has identified 65 elements in the star, HD222925. Forty-two of the elements identified are heavy elements that are listed along the bottom of the periodic table of elements.

Identifying these elements in a single star will help astronomers understand what’s called the “rapid neutron capture process,” or one of the major ways by which heavy elements in the universe were created...

Neutron star. Credit: NASA

A team of scientists from The Hebrew University of Jerusalem suggests a solution to the Galactic radioactive plutonium puzzle. All the Plutonium used on Earth is artificially produced in nuclear reactors. Still, it turns out that it is also produced in nature. “The origin of heavy elements produced in nature through rapid neutron capture (‘r-process’) by seed nuclei is one of the current nucleosynthesis mysteries,” Dr Hotokezaka, Prof Piran and Prof Paul from the Racah Institute of Physics at the Hebrew University of Jerusalem said in their letter. Plutonium is a radioactive element. Its longest-lived isotope is plutonium-244 with a lifetime of 120 million years.

Detection of plutonium-244 in nature would imply that the element was synthesized in astrophysical ph...