Physics professor uncovers surprising results from nuclear reactions inside stars
Image of a neutron star merger remnant. The magnetic fields inside them might be quite high, which will change how the electrons behave in nuclear reactions and how nuclear reactions behave. (NASA image)
KALAMAZOO, Mich.—Where do our elements come from? And how are they made? Dr. Michael Famiano's new research is flipping the script on those age-old nuclear astrophysics questions. The truth is out there—several light years away among the stars, to be exact.
"I'm wearing a ring on my finger. That gold was made in space somehow. And we think we have a pretty good idea of where it came from, but there's still lots of questions," says Famiano, professor and chair of Western's Department of Physics.
Along with colleagues at University of Wisconsin, Kyushu University in Japan and the National Astronomical Observatory of Japan, he's been studying the environments inside stars where heavy metals are made—places where violent collisions and reactions could produce enough heat to create matter and antimatter.
"Things get hot enough that it's possible to make electrons and positrons, and that changes everything we know about the environments that make elements," he says.
Those high temperatures are exacerbated by the extremely high magnetic fields found in space. Magnetic fields of neutron stars, for example, are about a quintillion times stronger than Earth's magnetic field.
"That changes the nuclear reactions, and it can change them pretty significantly and in pretty surprising ways," says Famiano. "And some of the stuff we're finding out is really interesting, because our results are almost counterintuitive."
Famiano will present his research at the fall meeting of the American Physical Society (APS) on Wednesday, Oct. 13. It will include preliminary data on the effects of high magnetic fields on accreting neutron stars. He'll explain how high magnetic fields in X-ray bursts can actually change the composition of the ashes as well as how electron capture rates relevant to cooling might actually decrease depending on field strength, which is the opposite of what was expected.
"It may actually explain some of the strange behavior that we see in stellar environments. And it's so broad-reaching because it affects anything that gets really hot and it affects anything that has a really high magnetic field. And you can always find that in space."
The APS conference runs from Oct. 11 to 14. More information about Famiano's presentation is available in the organization's bulletin online.
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