Neutron stars are some of the most exotic objects in the universe. The leftover cores of long-dead massive stars, they are macroscopic objects with densities of atomic nuclei. The gravitational pull at the surface is so intense that "mountains" are barely centimeters high, and a fall from that height would reach a terminal velocity of tens of thousands of miles per hour.
Though they are composed almost entirely of neutrons, there are protons scattered within the interior. Neutron stars also spin incredibly rapidly, a natural consequence of the conservation of angular momentum as the much larger progenitor star collapsed to much smaller volumes. The remaining electrical charge generated by the surviving protons, combined with the fast rotation, produces tremendous magnetic fields.
The magnetic fields are peculiarly strong; indeed they are the most powerful known magnetic systems in the universe, clocking in at an easy trillion times stronger than the Earth’s own field. At a distance of 620 miles (1,000 kilometers), the magnetic fields are strong enough to disrupt molecular bonds and reshape atoms themselves.
The magnetic field is constantly changing, which produces an electric field, which goes on to generate a new changing magnetic field. The end result of this interplay is a beam of radiation escaping the magnetic poles of the neutron star. If the magnetic poles aren’t aligned with the axis of rotation (like what occurs on the Earth), the beam of radiation sweeps a circular pattern into deep space.
If the beam flashes over the Earth, we can detect a pulse of radio emission with every rotation — hence the name "pulsars."
"We Don't Planet" is hosted by Ohio State University astrophysicist and COSI chief scientist Paul Sutter with undergraduate student Anna Voelker. Produced by Doug Dangler, ASC Technology Services. Supported by The Ohio State University Department of Astronomy and Center for Cosmology and AstroParticle Physics. You can follow Paul on Twitter and Facebook.
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Paul M. Sutter is an astrophysicist at SUNY Stony Brook and the Flatiron Institute in New York City. Paul received his PhD in Physics from the University of Illinois at Urbana-Champaign in 2011, and spent three years at the Paris Institute of Astrophysics, followed by a research fellowship in Trieste, Italy, His research focuses on many diverse topics, from the emptiest regions of the universe to the earliest moments of the Big Bang to the hunt for the first stars. As an "Agent to the Stars," Paul has passionately engaged the public in science outreach for several years. He is the host of the popular "Ask a Spaceman!" podcast, author of "Your Place in the Universe" and "How to Die in Space" and he frequently appears on TV — including on The Weather Channel, for which he serves as Official Space Specialist.