The Fantastic Physics of Neutron Stars

Dr. Jake Roark, the Science Guy

Hello all! My name is Dr. Jake Roark, the newest member of the STEM Education Works team – a Curriculum and Outreach Specialist. And no, I’m not the kind of doctor you can go to for a checkup. In graduate school, I studied astrophysics and today I’d like to share some stellar facts with you about some of the densest, most extraordinary objects in the universe: neutron stars.

Stellar Explosions

For a little under six years, I earned my Ph.D. in theoretical nuclear astrophysics at Kent State University researching the interior of neutron stars and the strange kinds of physics we might find there. Neutron stars are the leftover remnants of very large, very old stars that have died in fantastic explosions called supernovae. These dense, neutron-rich bodies typically have masses between one and two times the mass of our Sun – but all packed tightly into a sphere just 20 to 30 km across (roughly the size of Cleveland)! This means second to black holes, neutron stars exhibit the highest material densities in the universe, with average densities a little over three times the density of a typical atomic nucleus. So in other words, that’s a lot of matter in a relatively small space. (Sorry stellar detritus, hope you’re not claustrophobic.)

Under the astronomical pressures resulting from such high densities, the neutrons, protons, and electrons (the particles that make up atoms) have a hard time sticking together. So the interior of a neutron star is just an ocean of free-floating subatomic particles. Think about it like this: Atoms are like constructed LEGO sets, whereas the interior of a neutron star is like what happens when you hit that LEGO set with a hammer: just a bunch of individual LEGOs detached from each other. If that isn’t impressive enough, some astrophysics models suggest that pressures near the core of a neutron star can get so high, even subatomic particles like neutrons can be “squeezed” until they break apart into even smaller particles called quarks!

That phase transition from subatomic particles (called “hadrons”) to quarks was the bread and butter of my research and dissertation in grad school. Thanks to the large-scale, physical consequences of this phase transition, there exists an exciting, dynamic interplay in the field of neutron star research between the observations of astronomers and the theoretical models of astrophysicists, making neutron stars opportune natural laboratories for studying nuclear physics. You can learn more about neutron stars in this video by Kurzgesagt.

Bringing Astrophysics to a K-12 Classroom

I’m looking forward to the future and am excited to bring my knowledge, experience, and background to you and our team here at STEM Education Works. Of course, graduate research and dissertations aren’t the easiest way to teach about neutron stars in grade school. For more information about engaging students in astronomy and astrophysics, check out our very own “Soar Through STEM” lesson on gravity, visit NASA’s STEM Engagement webpage, and visit PBS’s Earth and Space Science webpage. And for a great tie-in with Black History Month, take a look at this article from ThoughCo. featuring 16 of history’s most influential black Americans in astronomy and space science (my favorites being Katherine Johnson and Dr. Arthur Bertram Cuthbert Walker II).