In galaxy NGC 3583, telescopes detected an unusual X-ray source: its brightness periodically spikes and then fades almost completely. Splitting this radiation into a spectrum (the distribution of intensity across energies, like a rainbow but in X-rays) astronomers found a narrow dark notch, a so-called absorption line. It's like a single note ripped from a musical chord: in the continuous spectrum, radiation at one specific energy is missing.

This spectral "note" is produced by protons trapped in the star's monstrous magnetic field. Here's how it works: in an ultra-strong field, the paths of charged particles are quantized, and protons can jump between discrete energy levels, absorbing or emitting photons of fixed energy. Just as a string pressed at a fret vibrates at a single frequency, protons interact with radiation only at a specific energy. The measured "pitch"—the energy of the absorption line — allowed astronomers to calculate the magnetic field strength: it turned out to be 400 trillion times stronger than Earth's magnetic field. This indicates that we are looking at a neutron star with record magnetism — a magnetar.

A magnetic field of this strength, according to the data, not only tears atoms apart, stretching their electron shells into thin needles along field lines, but also turns the surrounding vacuum into something like crystal: under its influence, empty space acquires properties of a medium that can bend the paths of light rays.