Magnetars: How Magnetic Fields Fool Light ⚡ экспресс
Magnetars boast magnetic fields up to 10^15 G, where Maxwell's linear electrodynamics breaks down and nonlinear electrodynamics (NED) emerges. This study explores NED's influence on photon propagation near magnetars. It shows that NED significantly alters light trajectories, deflecting them from standard null geodesics. Neglecting these corrections in ray tracing leads to a relative error in determining the star's radius of about 10%. Moreover, NED introduces a systematic minimal propagation time delay of around 350 ns — far exceeding the 100 ns temporal resolution of NICER mission instruments. These results are crucial for analyzing X-ray pulse profiles from both current and future observatories (eXTP) that rely on precise light-bending and timing models to measure neutron star masses and radii. The findings highlight magnetars as a unique window into the physics of ultra-dense matter and supercritical fields; other astrophysical observables like glitches and anti-glitches, which NED may influence, are briefly discussed.
Neutron stars are the ultra-dense remnants of stars, where matter is compressed to the limit described by Subrahmanyan Chandrasekhar. Magnetars are a type of neutron star with a magnetic field a quadrillion times stronger than Earth's. Normally, light passing a massive body bends because spacetime is warped—it acts like a gravitational lens. But in magnetars, the field adds a second lens: the light bends even more. It's like looking through glasses with double lenses: one from gravity, one from magnetism. Without accounting for the second lens, the error in radius reaches 10%.
Future telescopes, analyzing the flicker of pulsars (discovered by Jocelyn Bell Burnell), will refine neutron star sizes. This will unlock the secrets of ultra-dense matter inaccessible on Earth. And 10% isn't just a number: for a neutron star, it's the line between stability and collapse into a black hole.
🎯 A magnetar with a 10¹⁵ G field can demagnetize all bank cards within 100,000 km—a quarter of the way to the Moon.